H2AX and posterior cortical atrophy: Researchers discovered that the decay of 223RaCl2 results in the formation of track-like patterns of DDR proteins, mainly 53BP1 (known as α-tracks) and gamma-H2AX (γ-H2AX) foci, in both peripheral blood mononuclear cells and tumor cells in patients with prostate cancer (PCa) treated with 223RaCl2 [53,54].