The ‘built-in’ endocytosis-dependent absorption pathway denotes the potential for intracellular drug delivery in the context of an ADC.38 Finally, the relatively minor role of FRα in physiological folate uptake (compared with RFC) in nonmalignant adult tissues, compared with its enhanced folate uptake in cancer, may offer increased potential therapeutic index as a drug target. The gene discussed is FOLR1; the disease is cancer.