CDKN1B and primary biliary cholangitis: The results of quantitative PCR showed a significant increase of p27kip1 mRNA levels in non-cirrhotic and cirrhotic patients with PBC compared to controls (2.1 ± 0.2 versus 1.3 ± 0.3, P = 0.04 and 9.3 ± 2.3 versus 1.3 ± 0.3, P = 0.0001, resp).