These findings suggest that YKL-40 may be a useful diagnostic marker for SLE, this is in concordance with Wcisło-Dziadecka et al. in 2009, who found that mean serum YKL-40 levels were almost twice as high in SLE patients in comparison to controls and also found no correlation between YKL-40 serum levels and SLE disease activity as measured by the SLEDAI [19]. The gene discussed is CHI3L1; the disease is systemic lupus erythematosus.