Medulloblastoma isthe most common brain cancer in children. The current treatment for it includestoxic chemotherapy drugs which leadsto severe long-term side effectslike cognitive impairment. Still, the treatment failsfor many patients because some of the cells within the tumor are insensitive to the chemotherapy. There is a clear lack of research that identifies and targetsthese cells. We present a new way of identifying the insensitive cells by color-coding all the cellsin the tumor and looking to see exactly which color cellssurvive chemotherapy treatment. We can then find drugsthat specifically target these problematic cells while sparing healthy ones, offering effective and safer treatment optionsfor patients.