NFKB1 and cancer: In the tumor microenvironment, macrophage-secreted TNFα activates NFκB in cancer cells, leading to increased deubiquitinase CSN5 (COP9 signalosome 5) gene transcription and expression, and CSN5 stabilizes PD-L1 protein by inhibiting its ubiquitination and degradation, resulting in cancer cell immune escape22.