PTGS2 and melanoma: The most studied ASA biomarker is cyclooxygenase-2 (COX-2)-mediated generation of PGE2, which may be relevant to melanoma development given its induction in the skin [13,14] and melanocytes [15] upon UV exposure, its suppression of skin immune responses [16], the upregulation of COX-2 during melanoma progression [17,18,19], and the role of PGE2 in promoting angiogenesis [20,21], cell migration [22], and invasion [23].