CHI3L1 and cancer: CHI3L1 binding activity was increased in a dose-dependent manner on H1299 cancer cells (Figure 3F and Figure S4F), while nCHI3L1 Abs decreased the fluorescence signals induced by rCHI3L1 protein (Figure 3G and Figure S4G), suggesting that the nCHI3L1 Abs prevented CHI3L1 protein from binding to its receptor on H1299 cells.