Further characterization of CK5+CK8+ basal-luminal-like hybrid cells will assess expression of additional basal epithelial markers, p63 and CK14, to determine if these cells are p63-CK5+CK8+CK14+ transitional progenitor cells or a novel treatment emergent cell in bone metastatic prostate cancer. Here, KRT5 is linked to metastatic prostate carcinoma.