CD40LG and dermatomyositis: Although we report a 10% prevalence of anti‐ACE2 IgM in the North American cohort, the true prevalence is unknown given the observations that i) anti‐ACE2 IgM disappears over time, ii) the time between DM symptom onset and first research blood draw in our cohort was 1.3 years in the anti‐ACE2‐IgM‐negative group, and iii) the effect of immunosuppression on anti‐ACE2 IgM titers is unknown.