The joint effects of the PD and T2D pathological signalling pathways are as follows: (a) increased levels of pro-inflammatory cytokines, TNF-α, IL-1β, and IL-6, that enhance oxidative stress and MT dysfunction [1,259,260,261,262,263,264,265,266,267,268,269,270,271], (b) impaired neuroplasticity and memory formation [1,272,273,274], and (c) the development and acceleration of neurodegenerative disorders [1,147,272,273,274]. Here, IL6 is linked to type 2 diabetes mellitus.