These effects of 5-FU on bcl-2 and bax gene expression levels are similar to those reported by Magné et al. [30], who found that treatment with ZD1839 and cisplatin plus 5-FU for 24 h induced apoptosis via the mitochondrial pathway in CAL33 cells (a human head and neck cancer cell line). This evidence concerns the gene BCL2 and head and neck cancer.