MKS1 and Meckel syndrome, type 1: (a) Immunoblots for total soluble β-catenin, phospho-β-catenin, cyclin D1 and β-actin (loading control) in either wild-type normal or MKS1-mutated immortalised human fibroblasts from an MKS patient (MKS-562) following treatment with MG-132 proteasome inhibitor (+) or vehicle control (-).