Cognitive decline in type 2 diabetes and heavy metal exposure is closely linked to disruptions in cholinergic neurotransmission and neurotrophic support, particularly through alterations in AChE activity and BDNF levels (Davarpanah et al., 2021; Mushtaq et al., 2014; Frasco et al., 2007). The gene discussed is BDNF; the disease is type 2 diabetes mellitus.