Appropriate management of chronic GVHD requires continuous recalibration of immunosuppressive treatment in order to avoid overtreatment or undertreatment. The intensity of treatment required to control the disease decreases across time. Manifestations of chronic GVHD improve or are absent when the intensity of treatment is above the threshold shown as the orange curve, and they worsen or recur when the intensity of treatment is below the threshold. The slope of the threshold varies among patients and can be determined only by serial attempts to decrease the intensity of treatment. Clinical tolerance is defined by the ability to withdraw all systemic treatment without recurrence of chronic GVHD.