-Cleaved caspase-1 activates constitutively the NALP3 inflammasome in human melanoma cells.-Activated fragments of caspase-1 (p20) and caspase-5 (p20) are observed in lysates of human metastatic melanoma cells without IL-1α stimulation.-Activated caspases mediate IL-1β secretion in human metastatic melanoma cells (autoinflammation mediated by IL-1 contributes to the development and progression of human melanoma). The gene discussed is CASP5; the disease is metastatic melanoma.