CD40LG and interstitial lung disease: When we defined RP‐ILD as progressive worsening of dyspnea secondary to ILD requiring hospitalization, supplementary oxygen, or intubation within 3 months of diagnosis of ILD, three of five patients with anti‐ACE2 IgM (60%) experienced RP‐ILD compared with 9 of 47 (19%) in the anti‐ACE2‐IgM‐negative group (P = 0.07).