Ruxolitinib sulfate is primarily used in the treatment of myelofibrosis, a rare bone marrow disorder. It helps reduce symptoms such as an enlarged spleen, night sweats, itching, and bone pain by targeting specific enzymes involved in the disease's progression. Additionally, it is effective in managing polycythemia vera, a condition where the body produces too many red blood cells, by controlling blood cell production and improving quality of life. In recent years, it has also shown promise in treating graft-versus-host disease (GVHD), a complication that can occur after a stem cell transplant, by modulating the immune response. Its application extends to certain autoimmune conditions due to its ability to inhibit pathways involved in inflammation.