In contrast, when the information of the anti-IgLON5 antibodies status is missing but the clinical history is compatible or the patient harbored the HLA-DRB1*1001 and HLA-DQB1*0501 alleles, then the diagnostic category of “probable anti-IgLON5-related tauopathy” should be applied. This evidence concerns the gene HLA-DRB1 and tauopathy.