Multiagent chemotherapy without or with biological response modifiers has shown higher response rates but has not impacted survival (Eggermont, 2006).
Another biological response modifier, interleukin 12, has shown activity in three separate clinical trials and increases CD8+ T-cell infiltrates in CTCL lesions (Rook et al, 1999b).
DTNBP1 is considered to be a modifier gene and has shown strong evidence of illness modification involving negative and cognitive symptoms [ 13].
Accumulating evidence from gene knockouts has shown that chromatin modifiers such as histone demethylases, histone methyltransferases and histone deacetylases have a critical role in male germ cell development [28], [29], [30], [31], [32], [33], [34].
Drosophila has shown similar variation in genetic modifiers of melanism, with yellow ebony, and tan variably implicated in driving melanic variation across species and natural populations [ 74- 78].
Of note, recent work has shown that doxorubicin increased levels of the posttranslational modifier ISG15, which resulted in ISGylation of the p53 family protein.
Recent work has shown that the loss of RB1 does not appear to initiate RMS, but is a disease modifier.
Herceptin is therefore one of the first biological response modifiers to have shown some clinical success and as such has led to its approval in the treatment of patients with c- erbB-2 overexpressing breast cancers.
Small ubiquitin-like modifier has been shown to be attached at lysines in the N terminus of huntingtin very near the polyglutamine stretch (Ross & Poirier, 2004).
However, we have shown previously that modifier SNPs in combination can result in large differences in the absolute risk of developing breast cancer for carriers at the extreme percentiles of the combined SNP distribution [ 5, 39].
