Study type: prospective, observational registry of Chinese marginal zone lymphoma (MZL) patients, treatments chosen by physicians per routine care. Drugs/interventions and mechanisms: Obinutuzumab—type II anti‑CD20 monoclonal antibody, promotes antibody‑dependent cellular cytotoxicity (ADCC) and direct B‑cell death. Rituximab—type I anti‑CD20 monoclonal antibody, mediates complement‑dependent cytotoxicity (CDC), ADCC, and apoptosis. Bruton tyrosine kinase (BTK) inhibitors (e.g., ibrutinib/zanubrutinib)—oral small‑molecule covalent kinase inhibitors, block B‑cell receptor (BCR) signaling via BTK, suppressing NF‑κB/MAPK survival pathways. Lenalidomide—oral immunomodulatory drug (IMiD), binds cereblon to degrade IKZF1/3, enhances T/NK cell activity, and has anti‑angiogenic/direct tumor effects. Target cells/pathways: malignant CD20+ B cells in MZL, BCR/BTK→NF‑κB signaling, immune effector pathways (ADCC/CDC) and T/NK‑mediated anti‑tumor immunity.