GAPDH and ductal breast carcinoma in situ: Following the implementation of breast screening programs, the occurrence of Ductal carcinoma in situ (DCIS) as an early type of neoplasia has increased.The current investigation verified the six core genes (containing GAPDH, CDH2, BIRC5, NEK2, IDH2, and MELK) signatures for prospective DCIS biomarkers, which may aid clinical decision‐making for individual care.