Furthermore, LC-MS/MS and RNA-seq assays reveal that SOS1 negatively regulates the expression of SLC22A4, a member of the carnitine/organic cation transporter family, which mediates the active uptake of imatinib into chronic myeloid leukemia cells. The gene discussed is SLC22A4; the disease is chronic myelogenous leukemia, BCR-ABL1 positive.