This study provides new insight into the multiple mechanisms involved in acquired doxorubicin resistance in breast tumour cells.  In addition to previously the known mechanism involving the increased production of the Abcc1 drug efflux transporter, the cells acquire doxorubicin resistance by sequestering the drug into lysosomes and by activating non-canonical autophagy through increased production of LC3-II and p62. This evidence concerns the gene ABCC1 and breast neoplasm.