| Gene Symbol | YKL |
| Full Name | 40 (Chitinase 3-Like 1) |
| Aliases | YKL-40 (N-terminal tyrosine, lysine, leucine, 40 kDa), HC-gp39, BRP-39 |
| Chromosome | 1q32.1 |
| Protein Family | Chitinase-like proteins (glycoside hydrolase family 18) |
| Function | YKL-40, also known as chitinase 3-like protein 1 (CHI3L1), is a secreted glycoprotein belonging to the glycoside hydrolase family 18[@chitinase2020]. |
| GeneCards | YKL |
| Human Protein Atlas | YKL |
| Gene | CHI3L1 located on chromosome 1q32.1 |
| Protein | 383 amino acids, ~40 kDa |
| Diagnostic utility | Elevated in AD vs. controls (AUC ~0.75-0.85) |
| Disease progression | Levels correlate with cognitive decline |
| Amyloid correlation | Modest positive correlation with amyloid burden |
| Tau correlation | Some studies show association with tau pathology |
| Databases | GeneCardsUniProtNCBI GeneHPASTRING |