Our gene expression microarray data show that MSCs isolated from the liver of patients with fibrosis or cirrhosis express several liver-specific genes: ribonuclease RNase A family 4 (RNASE4), CYP1A2, γ-glutamyl transpeptidase (GGT1), and glutamine synthase (GLUL)—at a low level; CYP1B1—at a relatively high level; a very high level of expression was observed only for the NNMT gene encoding the nicotinamide N-methyltransferase. The gene discussed is NNMT; the disease is fibrosis.