ABCG2 and neoplasm: These findings may be of particular interest as other common drugs employed in non-neoplastic diseases that are substrates for the ABC transporters have been reported to select for increased ABCB1 in tumour cells following in vivo treatment (Herzog et al, 1993) and to confer resistance to doxorubicin in a tumour system (Granzotto et al, 2004).