Platelets are commonly known for hemostasis and coagulation as their major role. However, it has been reported that cancer’s growth, metastasize, and avoiding immunity system get help from platelets. Also, cancer cells both directly and indirectly affect the RNA content of platelets, changing the expression of platelets. This patent is on the basis of the background that platelets are potential biomarkers to help diagnose cancer due to that change of tens of thousands of platelets from out of one cancer cell.