Waldenström macroglobulinemia (shortened to WM) is a rare blood cancer. WM usually progresses slowly; some people do not show symptoms for several years after diagnosis. A person who does not have symptoms usually does not need treatment, but active monitoring is essential so that treatment can be started as soon as it is needed. Although there is no cure for WM, different treatment options can keep the disease under control for many years in a lot of people. Eventually, the treatments tend to lose their effect. New therapies are being tested in clinical trials across the world, with promising results.