Supershift assays using antibodies to homeodomain proteins, and the detection of endogenous expression of homeodomain proteins. Supershift assays were performed with the nuclear extracts from HEL (A), HepG2 (B), HeLa (C), and K562 (D) cells. (–) indicates no antibody. Arrows indicate the supershifted bands. (E) Endogenous expression of MEIS1, PBX1, and PBX2 was detected by Western blotting using 20-μg nuclear extracts from each cell line. The asterisk denotes the existence of a faint band.