ECRG4 and nasopharyngeal carcinoma: In nasopharyngeal carcinoma, the overexpression of Chromosome 2 open reading frame 40 (C2orf40) regulates the PI3K/AKT/mTOR pathway, significantly reducing the protein expression levels of key cell cycle regulators, including Cyclin-dependent kinase 1 (CDK1), Cyclin E1, and Cyclin B1.