Clinical efficacy of dasatinib monotherapy in the treatment of CNS leukemia in an index patient with relapsed Ph⁺ ALL. CSF blast count was performed from May-Grünvald-Giemsa–stained cytospin slides by counting 100 to 300 cells. Microscopy slides were viewed with Zeiss Axioskop 40 light microscope (Carl Zeiss Microimaging, Jena, Germany) using Plan-Apochromat 63×/1.4 oil and Plan-Neofluor 100×/1.3 oil objective lenses. Images were acquired using Axiocam HRC digital camera (Carl Zeiss Microimaging) and were processed with Axiovision AC 4.2 software (Carl Zeiss Microimaging).