TP53 and renal cell carcinoma: Transglutaminase 2 (TGase 2, E.C. 2.1.2.13) is an enzyme that catalyzes an isopeptide bond between protein glutamine and lysine residues, resulting in a covalent crosslink.1 Previously, we found that, in renal cell carcinoma (RCC) cell lines, TGase 2 crosslinks p53 into aggregates in the autophagosome, resulting in p53 degradation by autophagy.2 This p53 instability allows tumor cells to evade apoptosis and grow.