KRT19 and breast cancer: This finding with recombinant proteins replicates an earlier observation that TGM2 and KRT19 form a complex in the cytosol of the SKBR3 breast cancer line, which, however, is a site that would favor the closed conformation of TGM2 because of its high guanosine-5′-triphosphate (GTP) and low Ca2+ concentrations (11, 19).