We did not find differences in the PENK levels at the diagnosis of AKI (172 ± 117 pmol/L vs. 262 ± 156 pmol/L; p = 0.172) or at the initiation of CRRT (178 ± 161 pmol/L vs. 268 ± 163 pmol/L; p = 0.232). The gene discussed is PENK; the disease is acute kidney injury.