AbstractThe human nm23‐H1 was discovered as a tumor metastasis suppressor based on its reduced expression in melanoma cell lines with low versus high metastatic potential. It encodes for one of two subunits of the nucleoside‐diphosphate kinase. Besides its role in the maintenance of the cells NTP pool, nm23 plays a key role in different cellular processes. The role of nm23‐H1 in these processes still has to be elucidated. Our goal was to identify Nm23‐H1 downstream targets by subjecting Nm23‐H1 overexpressing CAL 27 cells oral squamous cell carcinoma (OSSC) to microarray analysis. The genes with changed expression patterns could be clustered into several groups: transforming growth factor β (TGFβ) signaling pathway, cell adhesion, invasion and motility, proteasome machinery, cell‐cycle, epithelial structural and related molecules and others. Based on the expression patterns observed we presume that nm23‐H1 might have a role in OSSCs, which should be confirmed by future experiments. © 2006 Wiley‐Liss, Inc.