Carboxylesterase-1 (114835) is a widely expressed serine esterase that is involved in the hydrolysis of multiple amide-containing and ester-containing endogenous and xenobiotic compounds including therapeutic agents such as methylphenidate, oseltamivir, angiotensin-converting enzyme inhibitors (e.g., trandolapril and temocapril), and anticancer drugs (e.g., capecitabin). In addition, CES1 is the primary enzyme responsible for metabolizing clopidogrel and its derivatives (summary by Lewis et al., 2013).