Josiah Lake was diagnosed with the disease in December 2009 when he was 7.
Last month, the family was told the Eaton Rapids fifth-grader had a relapse.
Kurt Lake tells the Lansing State Journal his son faces another round of chemotherapy before having bone marrow transplant surgery either next month or in February.
Jason Evans is a friend of the Lake family. He says he hopes the money he raises will help the family defray some of the surgery-related costs not covered by insurance.
Evans plans to start his run about 6 a.m. Wednesday at Riverside Park in his hometown of DeWitt. He's still accepting pledges and donations.
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