PIK3CD and neoplasm: As for the tumor-promoting mechanism, PTTG3P overexpression upregulates pituitary tumor-transforming 1 (PTTG1), activating the PI3K/AKT pathway and enhancing HCC growth, cell cycle progression, EMT, and metastasis in HCC (Huang J. L. et al., 2018; Li et al., 2022).