I would ask for the pleasure of your company, Mr. Knightley, but I am a very slow walker, and my pace would be tedious to you; and, besides, you have another long walk before you, to Donwell Abbey.
I am a mageirocophobic. There, I've said it. My mother has mageirocophobia, and her mother wasn't so hot in the kitchen either.
Certain gene functions, however, are inherently dosage-sensitive (Fisher and Scambler, 1994). These include:
gene products that are part of a quantitative signaling system whose function depends on partial or variable occupancy of a receptor, DNA-binding site, etc.;
gene products that compete with each other to determine a developmental or metabolic switch;
gene products that co-operate with each other in interactions with fixed stoichiometry (such as the α and β globins or many structural proteins).
In each case the gene product is titrated against something else in the cell.