Inhibin-betaC is a recently described TGF-beta family member most homologous to inhibin-betaA and inhibin-betaB. By Northern analysis, inhibin-betaC mRNA was detected exclusively in the liver among a large number of adult mouse tissues surveyed. The expression of inhibin-betaC mRNA in adult liver dropped sharply and transiently following partial hepatectomy. At 6 and 12 hours following partial hepatectomy, the levels of inhibin-betaC mRNA were at least 8-fold lower than in control animals. The liver specificity of inhibin-betaC expression and its down-regulation following partial hepatectomy suggest that inhibin-betaC may function as a negative regulator of liver growth.