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.
What is Collagen? Collagen is the largest and most abundant protein in the body, making up about 30 to 35% of the total protein. Collagen is in every tissue of the body and is the connective tissue in structures such as skin, hair, nails, bones, lungs, heart and liver. It is often referred to as the glue that holds the body together. Collagen contains glycine, proline, and hydroxyproline, the three amino acids the body uses to manufacture its own collagen.