SDK1 and breast cancer: The analysis of primary HER2-positive breast cancers that were obtained from premenopausal Asian women with recurrent breast cancers showed some differences in the rate of several genetic abnormalities, compared to corresponding non-Asian premenopausal breast cancers: particularly, TP53, KTM2D, KMT2C, and SDK1 gene alterations were significantly more frequent in Asian than in non-Asian HER2-positive breast cancer patients [83].