MAPKAP1 and liver cancer: Activated AKT is found in ~50% of human HCCs,21 and AKT activation requires an intact mTORC2.23 In addition, previous studies showed that chromosomal gains at Rictor locus and Rictor overexpression are present in a subset of human HCC samples and associated with early tumor recurrence.13, 23 Interestingly, our most recent analysis using the TCGA data set suggests that mSin1, another unique mTORC2 component, is upregulated in human HCC samples (Che L, unpublished data), further supporting the role of mTORC2 in human liver cancer.