According to a paper published by Hao et al. in 2016 PIK3CA mutations lead to an upregulation of glutamate pyruvate transaminase 2 (GPT2) in CRC cells via ATF4 (activating transcription factor 4)/PDK1/RSK2 (ribosomal S6 kinase 2) in an AKT-independent manner ultimately rendering the cells dependent on glutamine [67]. This evidence concerns the gene ATF4 and colorectal carcinoma.