SUMO1 and breast cancer: Lin et al. (2016) suggested that global SUMOylation occurs through the phosphorylation of Ubc9 and SUMO1 directly mediated by AKT1. Thus, AKT1 is suggested to play an important role in the SUMOylation of a large number of substrate proteins in the cells. Furthermore, the SUMOylation of TFAP2A transcription factor is involved in the transition from the luminal subtype to the basal-like subtype of breast cancer (Bogachek et al., 2014).