Although some studies have reported that there was no significant correlation between CYP2C8 gene polymorphism and patients’ response to HCQ [10], our previous research showed that SLE patients with the CYP2C8 (rs10882521) GT genotype who took the same dose of HCQ had lower blood concentration than those with other genotypes, indicating that this SNP is related to the blood concentration of HCQ [21]. This evidence concerns the gene CYP2C8 and systemic lupus erythematosus.