Interestingly, each of the three human orthologs of TSP-21 (TSPAN4, TSPAN9 and CD53), as well as two out of the six human orthologs of TSP-12 and TSP-14 (TSPAN10 and TSPAN33), are expressed at elevated levels in certain cancer cell lines or tumors [73–75] In addition, one human ortholog of TSP-12 and TSP-14 (TSPAN14) is genetically altered in non-small-cell lung cancer [76]. Here, CD53 is linked to cancer.