ITPR2 and hyperinsulinemic hypoglycemia, familial, 4: The qPCR assay also revealed novel genes influenced by relaxin deficiency, including nicotinic cholinergic receptor type β1 (Chrnb1), encoding cyclic nucleotide gated channel α4 (Cnga4), inositol 1,4,5-triphosphate receptor-2 (Itpr1) and inositol 1,4,5-triphosphate receptor-2 (Itpr2), which were all significantly upregulated by 2-fold or more (P < 0.05, Figures 6D–H; Table 2).