Tumor

Definition

A tumor is an abnormal mass of tissue that results from excessive cell division, which can be benign or malignant. Malignant tumors are cancerous and have the potential to invade surrounding tissues and spread to other parts of the body.

5 Must Know Facts For Your Next Test

1. Tumors can evade immune surveillance by expressing immune checkpoint molecules such as PD-L1.
2. The immune system can sometimes recognize and destroy tumor cells through mechanisms involving cytotoxic T lymphocytes and natural killer cells.
3. Tumor microenvironment plays a critical role in modulating immune responses against the tumor.
4. Immunotherapy, including checkpoint inhibitors and CAR-T cell therapy, is emerging as a promising treatment for various types of cancer.
5. Tumors may secrete immunosuppressive factors like TGF-beta to inhibit effective immune responses.

Review Questions

Related terms

Cancer:

A disease characterized by uncontrolled cell division leading to the formation of malignant tumors.

Immunotherapy:

A type of cancer treatment that helps your immune system fight cancer.

Checkpoint Inhibitors:

Drugs that block proteins made by some types of immune system cells, such as T cells, which help keep immune responses in check.