CDK4 and breast cancer: The efficacy of selective CDK7 inhibitors, namely, CT-7001 (NCT03363893) and SY 5609 (NCT04247126), alone or in combination with other therapies in patients with advanced solid tumors, including advanced HR+/HER2− BC patients that progressed on CDK4/6i plus ET, is currently being investigated, as reviewed by [243].