Cellular resistance is a significant component of tumour treatment failure. More detailed understanding of resistance mechanisms has enabled us to plan circumvention strategies, though these are not yet in routine clinical use. Such resistance is, however, only one of several factors which render cure of advanced malignant disease difficult. It is important for researchers in this field to see not only therapeutic opportunities but also limitations of these approaches. It is hoped that increased cooperation between clinicians and scientists in the field of cellular resistance will yield further improvement in tumour response rates and cure.