MAPKAP1 and lipoma: In order to see whether Ras-mSIN1 interaction plays a role in the activation of mTORC2 via other stimuli, such as PTEN deficiency and rapamycin treatment, we next examined the effect of P4 in the PTEN-deficient cell line PC-3 and PTEN-haploinsufficient lipoma cells LipPD1, LipPD2, and LipPD3 [35].