There was a suggestion that patients who were ‘triple-positive’ for autoantibodies against all three GBM components exhibited a more severe disease phenotype, with a greater proportion of patients developing a composite end point of end-stage kidney disease or death compared with those positive for either anti-α3(IV)NC1 alone or the combination of anti-α3(IV)NC1 and anti-LM521. This evidence concerns the gene COL18A1 and glioblastoma.