At the protein level, normal iPSC-ECs predominantly expressed the mature LDL receptor, whereas FH iPSC-ECs showed a marked reduction in the mature form, with one line accumulating immature LDLR in the endoplasmic reticulum and the other displaying an overall depletion of both immature and mature receptor species; functionally, this translated into almost complete loss of fluorescent LDL uptake in FH-derived endothelium despite preserved endothelial identity. Here, LDLR is linked to familial hyperaldosteronism.