To demonstrate the utility of our novel anti-CD133 antibody for assessing modulation in tumor CSC phenotype, we applied CD133 47–10 to tumor tissue sections from xenograft models treated with the FAK inhibitor VS-6063 (defactinib; formerly PF-04554878), which preferentially targets CSCs and has been shown to reduce metastatic outgrowth in TNBC xenograft models [13]. The gene discussed is PTK2; the disease is neoplasm.