CD8A and neoplasm: Identifying GSK3 inhibitors, such as GSK3i and SB415286, are important because they not only inhibit the PTEN/PI3K/AKT signaling pathway, but they also downregulate transcription of PD-1 in CD8+ T cells, which activates CD8 cytotoxic T cells and decreases tumor proliferation, invasion, and cell cycle progression [160].