Of note, anti-Sj/﻿ITPR1-IgG was of the strongly complement-activating IgG1 subclass in the severely affected patient 1 (as well as in the severely disabled anti-﻿Sj/ITPR1-IgG index patient [1]), but exclusively of the very weakly complement-activating IgG2 subclass in patient 2, who had relatively mild disease with no major progression of his polyneuropathy after 1.5 years. The gene discussed is ITPR1; the disease is polyneuropathy.