To examine whether differential expression of Fat4 and Dchs1 could contribute to PCP in the sternum, the expression of Fat4 and Dchs1 was determined by immunolocalisation at E12.5 and E13.5, and their expression levels were quantified against either N–K-ATPase or β-catenin (Fig. 5a,c,e,g,i). Here, DCHS1 is linked to pneumocystosis.