ULK4 and acute promyelocytic leukemia: To determine whether SUMOylation and SIM mediates Ulk4 condensation as is the case for promyelocytic leukemia (PLM) bodies (Shen et al., 2006), we co-expressed Stk36-EE with wild-type (Ulk4-WT), SUMOylation deficient (Ulk4-K1030R) or SIM-mutated Ulk4 (Ulk4-ΔSIM) in HEK293T cells.