At high doses of H2O2 (100 μM), the presence of sildenafil increased RAD51 recruitment exclusively in SSc Hfbs (100 μM H2O2 vs. 100 μM H2O2 + S: 15.8 ± 3.6 vs. 32.0 ± 3.9, p < 0.01). Here, RAD51 is linked to systemic sclerosis.