Heat Shock Factor 2 Protects against Proteotoxicity by Maintaining Cell-Cell Adhesion, 2020, Joutsen et al

I can't remember to have seen HSF2, but HSP27 and HSP90 have been looked at previously in "Chronic fatigue syndrome: acute infection and history of physical activity affect resting levels and response to exercise of plasma oxidant/antioxidant status and heat shock proteins". I wish more studies would go into what could potentially go wrong after exertion, such as this.

 

I do think that cadherins are worth looking at more.

Toxins from some dinoflagellates disrupt cadherin function. This may be a mode of action in ciguatera fish poisoning (CFP). Some people affected by CFP go on to develop a chronic illness that is a lot like ME/CFS. (I haven't looked into this in detail, but just wanted to note the potential similarity.)

 

Yes There are some more studies from around the same time period as the one I posted above, though if I remember correctly they are all small and criteriria for diagnosis doesn't contain PEM.