PIK3CA and cancer: Given the previous studies demonstrating the role of the B55/B56 methyl-sensitive PP2A heterotrimers in regulating gene expression by targeting multiple signaling pathways such as PI3K/AKT/mTOR activation17–20, one critical function of C subunit methylation by LCMT1 could be to coordinately regulate both B55/B56 containing heterotrimers to negatively affect transcription and survival signals in cancer.