Indeed, increased propensity to develop FMF (determined based on higher allele frequency) was found for serum amyloid A (SAA)1.3 and for human leukocyte antigen (HLA)B39:01 in Japanese populations [31,32], The effect of the HLAB39 locus was more pronounced in patients bearing non-classical MEFV mutations. Here, MEFV is linked to familial Mediterranean fever.