An independent variable is the variable that the scientist changes,  and the dependent variables are the variables that the scientist  doesn't control.
Glycoprotein VI (platelet) also known as GPVI is a glycoprotein receptor for collagen which is expressed in platelets. In humans, glycoprotein VI is encoded by the GPVI gene.
A polypeptide molecule, collagen is a protein in our bodies. In fact, collagen is the largest and most abundant protein in the body, making up about 65% of our total protein. Proteins are made of amino acids, such as glycine, proline, arginine, hydroxyproline, which are amino acids that exist in collagen in varying proportions, depending upon the source.