CD4 and neoplasm: In studies involving melanoma and pancreatic tumors, intraperitoneal CPS treatment activated CD4+ T cells and elevated tumor-specific IgG antibody titers, which, while exerting less pronounced inhibitory effects on primary tumors (Sanders et al., 2016), played essential roles in tumor prognosis, immune memory, and long-term protective effects against tumor recurrence (Baird et al., 2013b).