Ruxolitinib is primarily used in the treatment of myelofibrosis, a type of bone marrow disorder that disrupts the body's normal production of blood cells. It works by inhibiting specific enzymes that contribute to the overactive signaling pathways causing the disease. This helps reduce symptoms such as an enlarged spleen, night sweats, and weight loss. Additionally, it is prescribed for polycythemia vera, a condition where the body produces too many red blood cells, helping to manage symptoms and reduce the risk of complications. Ruxolitinib is also being explored for its potential in treating other inflammatory and autoimmune conditions due to its ability to modulate immune responses.