Figure S4. Immortalized normal blood cells were resistant to ATRA. a Pin1 protein levels in two immortalized normal blood cells (N1 and N5 cells) were assayed by immunoblotting and compared with AML cell lines (HL-60, U937 and KG-1a). N was indicated normal blood cells. b After 3Â days treatment of different concentrations of ATRA, cell growth rates were determined by CellTiter-GloÂŽ 2.0 Assay. N1 and N5 cells were completely resistant to ATRA, compared with leukemia cell lines. (PDF 222 kb