PIK3R1 and neoplasm: Mechanically, IL-23 and PD-1 mAb both decrease the expression of Phosphoinositide-3-Kinase Regulatory Subunit 1 (PIK3R1), which is a regulatory subunit of PI3K and inhibit p110 activity, thereby promoting the subsequent activation of AKT pathways in tumor-specific cytotoxic T lymphocytes (CTLs).