 Recent advances in understanding the pathology of autoimmune diseases have led to the development of novel therapies targeting B cells. These include the use of monoclonal antibodies against CD20, which are effective in treating certain types of autoimmune diseases. Flow cytometry can be used to monitor the efficacy of these treatments by measuring changes in the number of B cells in the peripheral blood. This can help clinicians to determine when to administer further doses of the drug or switch to another type of treatment if necessary. This article was authored by Bruno Brando, Arianna Gatti, Alfredo Maria Lerotti and others.