AKT1 and breast cancer: However, it is also possible that there is a yet to be uncovered role for ubiquitination in regulating the activity of different AKT isoforms, which have been associated with opposing effects on breast cancer cell migration and invasion (Maroulakou et al., 2007; Chin and Toker, 2011; Chen et al., 2020), or in modulating AKT activation in specific subcellular locations (Sugiyama et al., 2019).