Vehicle treatment (i.e., withdrawal of abemaciclib) led to acceleration of tumor growth accompanied by increased tumor cell proliferation and Rb phosphorylation, consistent with the notion that CDK4/6i continue to play some antiproliferative role in these tumors, even in the setting of resistance (Fig. 4E; Supplementary Fig. S10E–S10G). The gene discussed is CDK4; the disease is neoplasm.