We have previously demonstrated that laminin modulates the expression of adhesion molecules in an adenoid cystic carcinoma cell line (CAC2 cells). We are currently studying whether laminin can induce modifications in the overall morphology of CAC2 cells. These cells were grown in a three-dimensional preparation of laminin-1. Phenotype differences were assessed by light and transmission electron microscopy. CAC2 cells grown inside laminin-1 formed ductlike and pseudocystic structures. Based on our findings we suggest that laminin is a key regulator of tubular and pseudocystic patterns of adenoid cystic carcinoma. We also analyzed the effect of a molecular domain of laminin-1, the peptide SIKVAV (Ser-Ile-Lys-Val-Ala-Val) on CAC2 cells. This peptide was chosen because it is effective in cell proliferation and differentiation, and because it has never been tested before in salivary gland neoplasms. When CAC2 cells were grown inside SIKVAV-enriched laminin-1, only pseudocystic structures were observed. Since no ductlike structures were observed in samples treated with SIKVAV, we may assume that this peptide is at least one of the molecular domains of laminin responsible for the pseudocystic pattern observed in adenoid cystic carcinoma. Function disturbing experiments strongly suggested that the integrin alpha3beta1 play a role in the effect of laminin on CAC2 cells.