The morphologic changes of the wild-type and transformant HL-60 cells on IPTG stimulation. (A) and (B) Wild-type HL-60 cells. (C) and (D) Mock-transfected HL-60 cells. (E), (F), (G), (H), (I), (J), and (K) NF-1 cells. (A), (C), and (E) Without IPTG. (F) With IPTG for 24 hours. (G) and (H) With IPTG for 48 hours. (I) With IPTG for 60 hours. (J) With IPTG for 84 hours. (B), (D), and (K) With IPTG for 96 hours. Original magnification: (H) × 1000, and others × 400.