, it has been shown that tumor cells resistant to cyclophosphamide acquire a mesenchymal character which promotes the expression of drug efflux pumps (ABCC1 and ABCB1) [109].During cancer progression, tumor cells are able to activate immune cells and fibroblasts which secrete different cytokines affecting cancer development and metastasis [110]. The gene discussed is ABCC1; the disease is neoplasm.