In conclusion, we have determined the status of pSTAT5 and pSTAT3 in a relatively small number of human ADH cases, and detected a reciprocal and complementary expression pattern of pSTAT5 and pSTAT3 in these lesions, suggesting that these lesions may be closer to normal breast epithelia than to DCIS or IBC in terms of regulation of STAT5 and STAT3 activities. Here, STAT5B is linked to ductal breast carcinoma in situ.