SEC63 and Isolated polycystic liver disease: Interestingly, the present analysis identified yet another multispanning plasma membrane protein, VANGL2 [179,180,181,182,183,184,185,186,187], that is involved in the establishment and regulation of planar cell polarity as a Sec63 client and, when absent, may also contribute to the phenotype of SEC63-linked polycystic liver disease (Table S4).