CSNK1A1 and neoplasm: So far, three CRL4CRBN substrates have been identified that mediate the anti-tumor activity of IMiDs in hematologic malignancies, including the Ikaros family zinc finger proteins 1 and 3 (IKZF1 and IKZF3) [57,58] and casein kinase 1 alpha (CK1α) [59].