Meroval is rituximab, a molecularly targeted drug used clinically for the treatment of CD20-positive follicular lymphoma and CD20-positive diffuse large b-cell lymphoma. Merova is a molecularly targeted drug that specifically binds to tumor cells to kill them. It must be used in conjunction with other chemotherapeutic agents to achieve greater effect, including cyclophosphamide, vincristine, dexamethasone and anthracycline. Merova has obvious side effects, the most common being allergic reactions, especially when used for the first time, patients often experience hypotension, flushing, high fever, rash and other allergic reactions, requiring experienced hematologists to use it in hospitals with resuscitation conditions, with the risk of anaphylaxis.