Abemaciclib treatment significantly sensitized ABCB1 or ABCG2 over-expressing cancer cells to respective chemotherapeutic drugs through impairing the “porter” roles of ABCB1 and ABCG2 in these transporters-amplified carcinoma cells, which implicated that abemaciclib could reverse the ABCB1 or ABCG2-induced multidrug resistance to some extent [72]. Here, ABCG2 is linked to carcinoma.