Some of this variability in toxicity is accounted for by variations in drug pharmacokinetics (PK) [30], differences in co-morbidity (cardiac, liver, or renal diseases), predisposing factors (gender and age), variability in dihydropyrimidine dehydrogenase (DPD), activity of peripheral blood mononuclear cells (PBMNC), telomere length (TL) or platelet lymphocyte ratio (PLR) [42]. This evidence concerns the gene DPYD and kidney disorder.