EGFR degradation - (Sep/24/2015 )

When added EGF 1nM to cancer cell lines (nasopharyngeal carcinoma), and found decreased expression level of EGFR; does this mean EGFR degradation? why added EGF induced decline of EGFR expression? Thanks.

How are you measuring the decrease? Is it possible that (if using western blotting) that the proteins are phosporylated after activation and this is blocking the antibody epitope?

but is it correct that EGFRs are degraded only after activation/phosphorylation? Process of ligand-binding, dimerization, phosphorylation, ubiquitination, .... all the way to either at the end either recycled back to cell surface, or degradation?