It is also important to note that the PHIs are likely to have different levels of selectivity for the PHD isoforms in cells and may, to varying extent, inhibit other members of the 2OG dioxygenase family (e.g. BIQ has been reported to inhibit the fat mass and obesity protein FTO in vitro (47)). Here, FTO is linked to obesity due to melanocortin 4 receptor deficiency.