passages.id: split_6_test_760_passage
passages.type: progene_text
passages.text: Cdk4 - and Cdk6 - immune complexes recovered from B cells following BCR - Fc gamma R co - cross - linking are devoid of coprecipitated D - type cyclins , indicating that inhibition of their Rb protein kinase activities is due in part to the absence of bound D - type cyclin .