FKBP4 showed significantly increased reactivity in primary breast cancer and carcinoma in situ compared with healthy controls (Desmetz et al., 2009) and might be putative prediction markers in discriminating malignant (Xiong et al., 2020) and drug-resistant of breast cancers (Ostrow et al., 2009; Yang W.S. et al., 2012). Here, FKBP4 is linked to breast cancer.