Comparison of histone γ-H2AX foci in PBMCs derived from control donors and unselected BC patients. DNA damage assessed by means of the histone γ-H2AX assay in non-irradiated (A) and in irradiated (B-D) PBMCs derived from unselected BC patients (triangles), as compared to the cells from apparently healthy donors (circles). Initial (B), residual (C - 0.5 Gy, 24 h, D - 2 Gy, 24 h) DNA damage were assessed in PBMCs after irradiation with 0.5 Gy (B, C) or 2 Gy (D) in vitro. Filled squares represent the mean values (± SD) for the respective group. “n.s.” indicates that the difference was not highly significant (p > 0.05).