GJA4 and myocardial infarction: Furthermore, single nucleotide polymorphisms (SNPs) in GJA4 (the gene that codes for Cx37) have previously been shown to be associated with myocardial infarction and atherosclerosis, suggesting (by analogy with the wide-ranging effects of mutations in HGF/MET and Cx47), that Cx37 could have a role in secondary lymphedema [16].