SPOP and cancer: In an attempt to elucidate the regulation of PI3K/Akt/mTOR signaling in RCC, we examined the activation of SPOP (also known as E3 ubiquitin ligase adaptor), the mutation of which has been shown to be positively associated with activation of PI3K/Akt/mTOR in human cancers such as prostate and colorectal cancers (Blattner et al., 2017; Xu et al., 2015).