Patients who received eculizumab had a slightly lower C3 complement level and higher maximal LDH measured at the moment of P-HUS diagnosis, but the results did not reach statistical significance (0.45 vs. 0.74 g/l, P = 0.061 for C3 and 112.25 vs. 94.65 μkat/l, P = 0.427), C3 was not obtained on the same day after P-HUS diagnosis (days 0–2) in all cases, and also LDH reached maximum levels on different days. The gene discussed is C3; the disease is hemolytic-uremic syndrome.