CDK4 and breast cancer: In an ongoing Phase Ib/II study (NCT04802759) involving breast cancer patients at locally advanced or metastatic stages who are ineligible for surgery and have previously received CDK4/6i or standard anti-HER2 therapy, the CDK7 inhibitor Samuraciclib (also known as ICEC-0942, CT-7001) is being investigated (Figure 4A).