Effects of eIF3f-hMSH4 on cellular response to IR. (A) Clonogenic survival analysis of 293T, 293T/eIF3f and 293T/eIF3f-hMSH4 cells treated with 1 or 2 Gy IR. Colonies that contained at least 50 cells were counted and the percentage of cell survival was determined in reference to untreated control cells. The means of three individual experiments and the corresponding standard deviations (error bars) are presented. (B) Examination of γ-H2AX foci formation at 6 or 24 hrs post-exposure to 10 Gy IR. Percentages of cells possessing 15 or more foci/nucleus are graphically presented, and statistically significant differences are indicated with asterisks (*p < 0.05 and **p < 0.01; Student’s t-test).