SFTPD and acute kidney injury: Serum SP-D level at day 1 (baseline SP-D level) of AKI patients ranged from 110.6 ng/mL to 199.5 ng/mL (median, 142.4 ng/mL; IQR 128.5 ng/mL-158.5 ng/mL), from 275 ng/mL to 393.2 ng/mL at day 3 (median, 342.2 ng/mL; IQR 323.2 ng/mL-356.1 ng/mL) and from 100.4 ng/mL to 159.9 ng/mL at day 7 (median, 134.8 ng/mL; IQR 125.6 ng/mL-146.5 ng/mL).