Taking into account the fact that CAND1 overexpression has been shown to promote cancer proliferation and metastasis in several cancers, including lung, prostate, and liver cancers [11,12,13,14,15], and that CAND1 interacts with miR-148b-3p, which is a mediator of ERα-positive breast cancer cell metastasis [17,18,19], it is crucial to investigate the prognostic value of CAND1 in ERα-positive breast cancer. Here, CAND1 is linked to breast cancer.