GPC1 and breast angiosarcoma: In a CNV study with 61 BA cases and 5,088 controls in an American cohort, Cui et al. observed a statistically significant increase in deletions at 2q37.3 in patients with BA that resulted in deletion of one copy of GPC1. Moreover, results as obtained by inducing GPC1 defects in zebrafish, revealed that the abnormal morphogenesis in intra- and extra-hepatic bile ducts of these zebrafish embryos led to reduced gallbladder uptake, while suppressing the Hedgehog pathway partially reversed this biliary tract defect in these GPC1 mutants.