Time dependence of PML-NBs induction after ionizing radiation. Fluorescence microscopic images of (A) fibroblasts and (B) PBMC before and after irradiation by X-rays stained with anti-γH2AX and anti-PML. The number of PML-NBs (C) and number of γH2AX foci (D) in irradiated cells using 2 Gy were counted at different times after irradiation. The black triangles represent fibroblasts and the white squares PBMC’s. Pearson’s correlation coefficients (r) and the p-values for the linear function are given (C).