Cancer cells can evade immune detection through several mechanisms:
Downregulation of MHC Molecules: Some tumor cells reduce the expression of MHC molecules, making it harder for T cells to recognize them. Expression of Inhibitory Molecules: Tumor cells may express molecules that inhibit T cell activity, such as PD-L1, which binds to PD-1 on T cells and suppresses their activity. Antigenic Variation: Tumor cells can alter their peptide repertoire to avoid recognition by specific T cells.