PIK3CA and breast cancer: In summary, we found that circ_6014 may inhibit breast cancer, serve as a ceRNA and participate in the proliferation of breast cancer cells through the circ_6014/miR-885-3p/NTRK2-PIK3CA/AKT axis (Supplementary Figure 3), which suggests that circ_6014 can be a potential biomarker and clinical therapeutic target.