CD177 and cancer: The SELEX process can be also applied to select aptamers targeting whole living cells (cell-SELEX, Figure 3) [21,22] providing an effective approach for, e.g., (i) identification of new biomarkers as disease signals in diagnosis and therapy [23,24], (ii) visualization and capture of cancer cells, (iii) targeting of cell surface receptors to increase the effectiveness of the immune system in cancer immunotherapy [25] and (iv) recognition of virus-infected cells [26].