A comparable pattern of morphological neuronal differentiation was induced in the human neuroblastoma cell line SMS-KCNR by treatment with either retinoic acid (RA) or exogenous laminin (LM). LM expression and synthesis by SMS-KCNR was increased upon RA treatment which involved the cell bound, rather than the secreted protein. These data suggest an involvement of LM in the neuroblastoma differentiation process manifested both as an ability of LM to induce a morphological neuronal differentiation and as a selective control on LM metabolism during RA induced neuronal differentiation.