ABCC1 and mature T-cell and NK-cell non-Hodgkin lymphoma: Over expression of the multi-drug resistant protein ABCC1 in PTCL may be the determinant factors for the decrease sensitivity to ATO, while cytotoxicity of organic arsenic species DAR is not altered in these cells because of ABCC1 is not the transporter of DAR, which resulting in increase DAR concentration in cells [171].