LCLs are widely used in pharmacogenomic studies and the applicability of LCLs for various clinical phenotypes is emerging. Early studies have yielded promising results for LCLs as a proxy for genetic variants for treatment outcome for a number of cancers as well as toxicity in varying tissue types including taxane-induced neuropathy. Although LCLs have demonstrated utility in the elucidation of functional mechanisms for results of clinical genotype-drug phenotype studies, there are more relevant cell-based models developing.