Folic acid is the form most commonly used in fortification and supplements because it is generally more bioavailable, more stable, and less complex than food folates. The appearance of methylfolate is largely due to developments in the science of human genetics, and the discovery of a particular ...
this is the key difference between ERK1 and ERK2. Furthermore, ERK1 protein in humans is comparatively large, while ERK2 protein in humans is comparatively small.