The prostaglandin E2 (PGE2) synthesis pathway, mediated by cyclooxygenase-2 (COX-2) and microsomal prostaglandin E synthase-1 (mPGES-1), plays a pivotal role in cancer progression by promoting tumor cell proliferation, angiogenesis, immune evasion, and metastasis. The gene discussed is PTGES; the disease is cancer.