Loss of heterozygosity (LOH) for bax was not found to be a part of mammary tumour development and progression in the C3(1)/SV40-Tag transgenic/bax-hemizygous murine tumour model (Shibata et al, 1999) nor in malignancies arising in arf-nullizygous/bax-hemizygous mice (Eischen et al, 2002). The gene discussed is BAX; the disease is neoplasm.