JAK1 and essential thrombocythemia: In this case, the patient had experienced progressive fatigue, dyspnea, and thrombocytosis over the preceding month, leading her hematologist to initiate ruxolitinib, a JAK1/2 inhibitor, as second-line therapy. Overall, this case illustrates the need for both diagnostic vigilance and collaborative treatment strategies in addressing the less common but serious venous manifestations of ET.