PDCD1 and breast carcinoma: On the other hand, simultaneous up-regulation of anti-apoptotic genes (e.g., PD-1 encoding programmed cell death protein 1) and down-regulation of immunity priming genes (e.g., MHC II encoding major histocompatibility complex II) help breast cancers escape detection and execution by the patrolling immune cells (Wang et al., 2017).