Interestingly, LDFRT treatment in both cell lines with or without Paclitaxel down-regulated nuclear factor kappa B activity and BCL-2 protein expression and simultaneously up-regulated BAX protein. Recent genetic studies with fibroblasts derived from mutant mouse embryos indicate that a class of the BCL-2 family proapoptotic proteins (designated BH-123 or multidomain proteins) such as BAX and BAK constitutes an essential component of the core apoptosis machinery in animal cells. No germ line BAX mutations were found.