Cell viability of K562 cells treated with Doxorubicin. (a) Cell viability was assessed using the 3-[4,5-Dimethylthiaoly]-2,5-diphenyltetrazolium bromide (MTT) method on K562shScr and K562shFHC cells treated with Doxorubicin at the indicated doses. Final results represent mean ± SD of three independent experiments each performed in triplicate (* p < 0.05; n.s., not significant, p ≥ 0.05). (b). Cell proliferation was assessed using the MTT method on K562shScr, K562shFHC/pRc/CMV and K562shFHC/Rc/CMV-HA-IκBα cells treated with Doxorubicin at the indicated doses and transfected with IκBα. Final results represent mean ± SD of three independent experiments each performed in triplicate; n.s., statistically not significant, p ≥ 0.05).