AK4 and cancer: BCL11B prevents senescence and apoptosis due to hyperactive Ras signaling.36 AK4 activates HIF1A and promotes epithelial-mesenchymal transition (EMT) under hypoxia and can reduce viability when knocked out in cancer cells.37 CD70 increases regulatory T-cell survival in tumors and is a potentially useful immunotherapy target.38 In all knockout lines, the most differentially abundant protein was the target of the knockout (data not shown).