Inclusion Criteria:

Subjects must meet all of the inclusion criteria to participate in this study:

- Diagnosed NPC, RCC, HCC or colorectal cancer patients. (Preoperative histologic
diagnosis is not required for RCC and HCC.)

- All stages of disease are eligible.

- Adult patients above 21.

- Ability to provide informed consent.     

Exclusion Criteria:

Subjects meeting any of the exclusion criteria at baseline will be excluded:

- Active infection.

- Immunocompromised or other active immune disorders.

- Have received chemotherapy or other immunomodulating therapy in the past 6 months.