We exposed murine prostate cancer cells (TrC1) as well as murine embryonic fibroblasts (MEF) to irradiation with equal doses of X-ray photons, plateau protons and Bragg-peak protons and determined the kinetics of DNA damage induction and repair, mainly DSBs, by quantification of protein foci, phosphorylated Histone 2A member X (γH2A.X), and p53-binding protein 1 (53BP1). The gene discussed is TP53BP1; the disease is prostate carcinoma.