Those sites of phosphorylation, the only ones reported in GJC3, are subject to genomic variation (Fig 11: the synonymous variant S227S [rs769486892 C/T] and T234N [rs140894833 C/A] and in the C-terminus from amino acids 219–279 there are 14 known somatic mutations including the neighbouring R220S (COSM219466, c.660G/T; breast carcinoma) and S228T (COSM4149446, c.682.T/A; carcinoma, ovary). Here, GJC3 is linked to breast carcinoma.