Genes expression of POU2F1, AR, PDK2, GSTZ1, GZMM, ACADS, ENOPH1, HCK, NDST1, and VAV2 are significantly related to the OS of breast cancer patients younger than 35 years (Fig. 10a), and POU2F1, AR, PDK2, GRHPR, SCO2, ACADS, ENOPH1, PPP2R1A, NUDC, and VAV2 are significantly associated with the RFS (Fig. 10b). Here, HCK is linked to breast cancer.