Bim is up-regulated during JAK2 inhibition-induced apoptosis in cells harboring activating JAK2 mutations. (A) Western blot analysis of bcl-2 family proteins. The cells were treated with 3μM JAK inhibitor I for 0, 6, 12, and 24 hours. (B) Dose-response of the JAK inhibitor I on phosphorylation of Bim. The cells were treated with JAK inhibitor I as indicated for 6 hours. (C) Real-time PCR analysis. The cells were treated with 3μM JAK inhibitor I for 0, 3, and 6 hours. Then, cells were harvested, total RNA was extracted, and mRNA levels were assessed by real-time PCR. The mRNA levels were normalized to those of GAPDH using the comparative threshold cycle method. Data are mean ± SD of GAPDH-normalized mRNA expression of 3 independent experiments. Error bars represent SD. *P < .05. **P < .01. N indicates not significant.