Regarding the association between HTLV‐1 infection and autoimmune diseases, we reported a low prevalence of anti‐Ro/SS‐A antibody in HTLV‐1‐seropositive SS patients.16, 17 A unique characteristic, that is, low prevalences of autoantibodies, was observed particularly in the HAM patients with SS. The gene discussed is CALR; the disease is tropical spastic paraparesis.