CHI3L1 and acute kidney injury: We speculate that the same is true for CHI3L1 as this protein has an apparent molecular weight of ±39–40 kDa [52, 53], and as within the group of patients with no AKI (in the 7-d prediction window) a concomitant very high level of SCHI3L1 was observed more in those with an increased than with a normal UCHI3L1 at enrollment (Additional file 1: Table S8).