sentences:  A significant number of JMML patients do achieve complete remission and long-term cure after a second bone marrow transplant, so this additional therapy should always be considered for children who relapse.JMML accounts for 1-2% of childhood leukemias each year; in the United States, an estimated 25-50 new cases are diagnosed each year, which also equates to about 3 cases per million children.There is no known environmental cause for JMML.