Why is it not surprising that signal receptors are overexpressed in most types of cancer?

This is because cancer cells are due to mutations proto-oncogenes or tumor suppressor genes that cause the biochemical and biological process of the cell to go into overdrive and failure of regulation by tumor suppressors. An example of a common cancer trait is an overexpression of growth factor receptors and G-protein–coupled receptors. It is through these receptors that cells receive information to regulate diverse processes, such as protein synthesis and cell growth, motility, cell architecture and polarity, differentiation, and programmed cell death. The overexpression of surface receptors, therefore, causes abnormal overexpression of the mentioned biochemical activities.

it has to be understood that the sea water contains a huge amount of sodium and chlorine ions and if they enter the cell of the atlantic cod fish, the cell will shrivel and the fish will die. to avoid such a condition, the fish uses active transport for the purpose of removing the ions against the gradient.

explanation:

the atlantic cod is not a maritime osmoconformer. its native application of salts is less than that of the seawater it lives in. it is continually falling water from the gills to the ocean via osmosis.

countering that, the fish is going to be swallowing seawater. but since its internal collection of salts is lower than seawater, the fish will want to go free of excess salt, and since that's going upon a gradient, then active transport, requiring energy, must be used to pump out the salt. much marine fish use the organs to filter out the salt and these fish discharge very straight urine.