The expression of TSPAN20/UPK1B (91), TSPAN1 (35), TSPAN8 (92), CD9 (93) and CD151 (30, 94–96) is positively associated with the clinical stage of gastric cancer and indicate a poor prognosis, while TSPAN5 (52), TSPAN21/UPK1A (57), CD82/KAI1 (97–100) are opposite. Here, CD9 is linked to gastric cancer.