t(11;18)MLT1-AP12 gastric maltoma HP+, persistent oral candidiasis, sinusitis; lung cystis, chronic cough, recurrent fever, hypereosinophilia, recurrent itch, recurrent myofasciitis, hyper-IgM, altered somatic hypermutation, absent CD19+CD20− IgG+ (mature), low CD19+CD27+IgM+ (memory), absent CD19+CD27+IgM− (switched memory). The gene discussed is CD19; the disease is gastric mucosa-associated lymphoid tissue lymphoma.