Previous work by our group, in addition to that of others, has shown that HER2 status was associated with radiotherapy resistance and that HER2 inhibition could enhance radiation sensitivity in HER2-positive breast cancer [17, 21, 22]; however, the trastuzumab-enhanced radiation sensitivity in HER2-negative breast cancer was considered a controversial topic [4]. Here, ERBB2 is linked to breast carcinoma.