CHEK2 and seminoma: Next, in order to investigate the level of activation of the DDR molecules in the seminoma TCam2 cells, we performed Western Blot hybridization with specific antibodies against pS1981_ATM (pATM), pT68_Chk2 (pChk2) and pS139_H2AX (γH2AX) observing a barely detectable signal, after 1 hour treatment with 10 μM H2O2 for all these DDR activation markers in TCam2 cells, compared to the levels observed in the GC1 normal testicular germ cells [18] (Figure 5C).