A candidate murine tumor-suppressor gene, Mom1, has been identified as the secretory phospholipase A2 (GDB nomenclature: PLA2G2A) gene. Evidence suggests that PLA2G2A functions as a tumor-suppressor because mice lacking PLA2G2A expression demonstrate increased colonic polyposis. The human homologue of PLA2G2A has been mapped to chromosome 1p36, a region frequently implicated in the pathogenesis of neuroblastoma, colon cancer and melanoma. We identified 2 alterations in the PLA2G2A gene in a single neuroblastoma cell line out of 20 examined; however, we found no mutations in 24 melanoma cell lines, 12 lymphoblastoid cell lines from patients having chromosome 1-linked familial melanoma and 10 colon cancer cell lines. Secretory phospholipase A2 is unlikely to play a significant role in the pathogenesis of these tumors.