PITX1 and hydrops fetalis: Whereas the skin sample keratinocyte populations were roughly divided between IFE and hair follicle (HF) populations (control: 48% IFE, 37% HF; PITX1+: 45% IFE, 39% HF), oral keratinocytes were only divided on stratified epithelial subtypes, reflecting the lack of hair follicles.