A more complex signal transduction pathway is shown in Figure 3. This pathway involves changes of protein–protein interactions inside the cell, induced by an external signal. Many growth factors bind to receptors at the cell surface and stimulate cells to progress through the cell cycle and divide . Several of these receptors are kinases that start to phosphorylate themselves and other proteins when binding to a ligand. This phosphorylation can generate a binding site for a different protein and thus induce protein–protein interaction. In Figure 3, the ligand (called epidermal growth factor (EGF)) binds to the receptor (called EGFR ). This activates the receptor to phosphorylate itself. The phosphorylated receptor binds to an adaptor protein ( GRB2 ), which couples the signal to further downstream signaling processes. For example, one of the signal transduction pathways that are activated is called the mitogen-activated protein kinase (MAPK) pathway. The signal transduction component labeled as "MAPK" in the pathway was originally called "ERK," so the pathway is called the MAPK/ERK pathway . The MAPK protein is an enzyme, a protein kinase that can attach phosphate to target proteins such as the transcription factor MYC and, thus, alter gene transcription and, ultimately, cell cycle progression. Many cellular proteins are activated downstream of the growth factor receptors (such as EGFR) that initiate this signal transduction pathway. [ citation needed ]
Hey, sorry for the super late reply. We’ve been traveling. It is more than likely allergies. Your vet can perform a fairly simply allergy test to confirm this and it should also be fairly inexpensive. Another reader above is experiencing similar issues. There are some steroidal creams and lotions you can get, but I always recommend speaking with a veterinarian first and getting their consultation. Chances are good that it’s nothing series; likely just an allergy to something in your house. You can try a quality purifier rated to remove dust mites, pollens, et cetera. Let us know!
Salicylate downregulates 11β-HSD1 expression in adipose tissue in obese mice and hence may explain why aspirin improves glycemic control in type 2 diabetes.  Epigallocatechin gallate from green tea can also potently inhibit this enzyme,  green tea is a complex mixture of various phenolics with contents varying with production and processing, some of the phenolics are known HDAC inhibitors that alter genetic expression. EGCG as usually consumed in green tea is poorly absorbed into the bloodstream, more research is needed to reach firm conclusions.