MYD88 and lymphatic system disorder: In both univariate and multivariate analyses, no single studied antigen was significantly associated with hyperviscosity syndrome, adenopathy, anaemia, serum IgM level, elevated β2‐microglobulin, cytogenetic abnormalities, MYD88 mutation, number of lines of treatment, international prognostic scoring system for WM, treatment response, progression‐free survival or overall survival (data not shown).