Other genes selected by PoPS include FLI1, a transcriptional regulator of blood and endothelial development [49], in a locus where SigNet selected KCNJ5, responsible for a Mendelian form of long QT syndrome [3], and KCNJ16, a potassium channel responsible for deafness [3], where SigNet selected KCNJ2, a different potassium channel responsible for Mendelian forms of atrial fibrillation and short QT syndrome [3]. The gene discussed is KCNJ2; the disease is Familial short QT syndrome.