ESR1 and neoplasm: Total tumor incidence was similar in WT and VDRKO mice, but VDRKO tumors were predominantly negative for ER and PR and exhibited transdifferentiation toward epidermis and hair. Glands from VDRKO mice showed impaired proliferative response to MPA stimulation compared with WT mice. Tumor histology in VDRKO mice was suggestive of wnt pathway activation.