Inclusion Criteria:

- Patients must have histologically or cytologically confirmed mantle cell lymphoma as
defined by the World Health Organization. All patients must have either a
demonstrated t(11;14) by karyotype, fluorescent in-situ hybridization (FISH) or
positive immunohistochemistry for cyclin D1.

- Subjects must have measurable disease, defined as at least one tumor mass of > 1.5 cm
in diameter.

- Subjects must have received at least one prior chemotherapy-containing regimen and at
least one prior rituximab-containing regimen.

- Age > = 18 years.

- Accessible disease, defined as at least one of the following:

- Adenopathy accessible to core needle biopsy

- Bone marrow involvement

- Circulating lymphoma cells in the peripheral blood

- ECOG performance status < = 2

- Patients must have normal organ and marrow function as defined below within 14 days
before enrollment:

- ANC > = 750 cells/uL

- platelets > = 75,000 cells/uL

- Hemoglobin > = 8.0 g/dL

- total bilirubin < = 1.5 times upper limit of normal

- AST(SGOT)/ALT(SGPT) < = 3 times upper limit of normal

- Calculated creatinine clearance > = 30 mL/min

- The effects of bortezomib and PD 0332991 on the developing human fetus at the
recommended therapeutic dose are unknown. For this reason, female subjects must
either be post-menopausal or surgically sterilized or willing to use an acceptable
method of birth control (i.e., a hormonal contraceptive, intra-uterine device,
diaphragm with spermicide, condom with spermicide, or abstinence) prior to study
entry and for the duration of the study. Male subjects must agree to use adequate
contraception prior to study entry and for the duration of study participation.
Should a female subject become pregnant or suspect she is pregnant while
participating in this study, she should inform her treating physician immediately.

- Voluntary written informed consent before performance of any study-related procedure
not part of normal medical care, with the understanding that consent may be withdrawn
by the subject at any time without prejudice to future medical care.

- Subjects must be willing and able to comply with the scheduled visits, treatment
plans, laboratory tests, and other procedures

Exclusion Criteria:

- Patients who have had chemotherapy, radiotherapy, antibodies, or investigational
agents within 4 weeks prior to entering the study unless progression has been
documented while on treatment, or those who have not recovered from adverse events
due to agents administered more than 4 weeks earlier. Patients may be receiving
prednisone at a maximum dose of 10 mg/day orally, provided the dose has been stable
during the prior two weeks before starting treatment.

- Patients may not be receiving any other investigational agents.

- Prior exposure to PD 0332991

- Prior exposure to bortezomib will only be permitted if there was a documented
complete or partial response and progression occurred off therapy

- Patients must not have experienced significant hematologic (grade 4) or neuropathic
toxicities (grade 3 or 4) due to prior bortezomib therapy

- Peripheral neuropathy > = grade 2 (CTCAEv3.0) within 14 days before enrollment.

- History of allergic reactions attributed to compounds of similar chemical or biologic
composition to bortezomib (e.g. boron or mannitol).

- Contraindication to serial core needle biopsies

- Known HIV infection

- Known malabsorption syndrome that may affect absorption of the drug

- Known or suspected CNS involvement

- Uncontrolled illness including, but not limited to, ongoing or active infection,
symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia,
or psychiatric illness/social situations that would limit compliance with study
requirements.

- Pregnant and lactating women are excluded from the study because the risks to an
unborn fetus or potential risks in nursing infants are unknown. Confirmation that
the subject is not pregnant must be established by a negative serum B-human chorionic
gonadotropin (B-hCG) pregnancy test result obtained during screening. Pregnancy
testing is not required for post-menopausal or surgically sterilized women.

- QTc > 470 msec

- Current use or anticipated need for food or drugs that are known potent CYP3A4
inhibitors, including their administration within 7-days prior to the first PD
0332991dose (i.e. grapefruit juice, verapamil, ketoconazole, miconazole,
itraconazole, posaconazole, erythromycin, clarithromycin, telithromycin, indinavir,
saquinavir, ritonavir, nelfinavir, lopinavir, nefazodone, diltiazem, atazanavir,
amprenavir,and fosamprenavir)

- Current use or anticipated need for drugs that are known potent CYP3A4 inducers,
including their administration within 14-days prior to the first PD 0332991 dose
(i.e. carbamazepine, dexamethasone, felbamate, omeprazole, phenobarbital, phenytoin,
primidone, rifabutin, rifampin, and St. John's Wort).

- Myocardial infarction within 6 months prior to enrollment or has New York Heart
Association (NYHA) Class III or IV heart failure (see Appendix 7), uncontrolled
angina, severe uncontrolled ventricular arrhythmias, or electrocardiographic evidence
of acute ischemia or active conduction system abnormalities. Prior to study entry,
any ECG abnormality at Screening has to be documented by the investigator as not
medically relevant.

- Diagnosed or treated for another malignancy within 3 years of enrollment, with the
exception of complete resection of basal cell carcinoma or squamous cell carcinoma of
the skin, an in situ malignancy, or low-risk prostate cancer after curative therapy.