Yet, as the interphase CDK2, CDK4 and CDK6 are not absolutely required for cell cycle progression, targeting these kinases should have fewer side effects than targeting the mitotic kinase CDK1.535 A pilot study using seliciclib, a CDK2, CDK7 and CDK9 inhibitor, showed a remarkable amelioration of the immune components of SLE. Here, CDK2 is linked to systemic lupus erythematosus.