CHI3L1 and COVID-19: At paired analysis, CHI3L1 plasma levels of COVID-19 survivors after hospital discharge (T1) were significantly lower compared with levels at admission (T0) (232.1 [126.0–942.0] ng/mL vs 118.5 [70.2–236.7] ng/mL, p < 0.0001, Fig. 1 panel C), although remaining higher than HC (p < 0.05).