Even in a study by Apostolski et al. (1991), it was shown that there is a significantly higher titer of IgG in the sera and CSF of patients with ALS (this study also showed a significantly increased mean value of the C4 component of the complement, as well as a significantly reduced value of THC – the total hemolytic titer complement). The gene discussed is C4A; the disease is amyotrophic lateral sclerosis.