As illustrated in Figure 7A, Patient 1, who was initially treated with Imatinib, a first-line tyrosine kinase inhibitor (TKI) specific for the BCR-ABL1 fusion protein in CML, showed a decrease in CLC counts from 105 to 7 per mL over a 45-day period, as determined by our microfluidic device followed by FISH testing. Here, BCR is linked to chronic myelogenous leukemia, BCR-ABL1 positive.