PIK3CA and melanoma: Moreover, Chen et al. also found that in melanoma cells, the BRAFV600E protein interacts with Rictor and restrains both mTORC2 and Akt activation, suggesting the existence of multiple layers of regulation through which active BRAF attenuates the overall output of RTK/PI3K/Akt mTOR signaling in drug-naïve melanoma cells [297].