Metastasis to distant sites is mediated by various receptors on the surface of tumor cells. B16-F1 melanomas surviving 43.5 degrees C heat in vitro for 15 minutes and cultured for 10 days bind significantly increased amounts of the basement membrane protein laminin. Motility of heat-resistant B16-F1 cells in vitro toward the chemoattractant laminin is significantly increased. The increased expression of putative laminin receptors may be associated with increased metastasis of melanomas after subcurative hyperthermia.