The lack of a discernible relationship between Ig and infection in some ocrelizumab cohorts may relate to factors including a focus on serious infection [13, 15], short duration of follow-up [14, 16], or the tendency to consider IgM and IgG as binary variables (above or below the lower limit of normal) [11, 29], which may over-simplify humoral protection. This evidence concerns the gene CD40LG and infection.