NR4A1 and breast cancer: CCI-779 and RAD001, the derivatives of rapamycin, have been proved by the FDA for treating some tumors such as advanced-stage renal cell carcinoma, pancreatic tumor, and hormone-receptor-positive advanced breast cancer [14, 15, 26], and RAD001 is also currently being tested as a single agent or in combination with additional therapies for the treatment of various cancer types [27].