HLA-DQA1 and narcolepsy-cataplexy syndrome: The analyzes revealed that ClK cells expressed HLA-DQA1 molecule and identified a narcolepsy-cataplexy associated allele (namely, HLA-DQB1*0602) (Lin et al., 2001), whereas no alleles associated with intestinal diseases (e.g., celiac disease, inflammatory bowel diseases) or co-morbidities were found (e.g., diabetes).