In a separate study, Wolf et al. used an antibody directed against the intracellular domain of membrane-bound Klotho to evaluate Klotho protein expression by IHC in a further 58 early-stage invasive ductal carcinoma samples, 47 pure ductal carcinoma in situ (DCIS) samples, and 11 normal breast samples [49]. This evidence concerns the gene KL and invasive ductal breast carcinoma.