PTEN and cancer: Owing to mutated activation of proto-oncogenes, such as PI3K and AKT, or mutated inactivation of tumor suppressors, such as PTEN, TSC1, and TSC2, the aberrant activation of the mTORC1 signaling pathway occurs frequently in many human cancers, including LSCC, which is associated with tumorigenesis and cancer progression 12-14.