Differential display PCR was used to study the effects of lithium on gene expression. Four candidate genes were isolated and verified by Northern hybridization after 1 week treatment of C6 glioma cells with therapeutically relevant concentrations of LiCl (1 mM). Sequencing analysis revealed three previously unidentified cDNA fragments in addition to a sequence with 99% homology with the cDNA for 2′,3′-cyclic nucleotide 3′-phosphodiesterase type II (CNPaseII). Since CNPaseII is important in myelinogenesis and possibly neuronal growth and repair, the present findings suggest that lithium treatment may regulate these processes.