While wupA encodes 11 TnI isoforms, the TNNI human counterparts are encoded in three different genes, TNNI1, TNNI2 and TNNI3. Based on the association between copy number variation and certain types of cancer (Catalogue of Somatic Mutations in Cancer: https://cancer.sanger.ac.uk/cosmic), and experimental tumor cell growth suppression, TNNI1 seems the closest homologue to wupA [18]. Here, TNNI2 is linked to cancer.