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.
Collagen is one of the most abundant proteins in the body and it makes up a large part of our skin, hair and nails. Technically a polypeptide, collagen contains a mixture of amino acids like proline and glycine, which are found in all connective tissue within the body (including vital organs!). (1)