Systemic and selective knockdown of PITPNM3 in CD4+ T cells achieved by intraperitoneal injection of CD4-AsiCs blocked recruitment of TI naive CD4+ T cells and development of TI Tregs, caused expansion of TI CD8+ T cells and increased intratumoral apoptosis, and strongly suppressed primary tumor growth and metastases. The gene discussed is PITPNM3; the disease is neoplasm.