CHRM4 and preeclampsia: One gene of interest is cholinergic receptor muscarinic 4 (CHRM4), a choline metabolism gene that is negatively correlated with circulating soluble factor fms-like tyrosine kinase-1 (sFLT1) concentrations; it is suggested that CHRM4 may play an as yet unknown regulatory role in sFLT1 production and preeclampsia pathogenesis [34].