Finally one study in which gingko biloba was more efficacious than placebo and equal to the second generation cholinesterase inhibitor donepezil (Mazza et al., 2006) was heavily criticized by two other groups (Corrao et al., 2007; Korczyn, 2007), making it difficult to estimate if the use of ginkgo containing herbal medicines are justified for the treatment of mild to moderate AD. The gene discussed is BCHE; the disease is Alzheimer disease.