GNB3 and Waardenburg syndrome: MITF has been associated with Waardenburg syndrome, characterized by pigmentation anomalies of eyes, hair, and skin.86–88 Previous work has also identified that MITF (melanocyte-inducing transcription factor) protein labeling in human tumor samples is strong around the vessels.89 Moreover, 2 of the GWAS loci identified across the FD and vascular density GWASs, namely GNB3 and GNB2, are G proteins and are known to be key moderators of chemokine signal transduction pathways.