Fcγ receptor III (CD16) of NK cells and L-selectin (CD62L) of T cells can be targets of aptamers for recruiting immune cells, and membrane receptors overexpressed in cancer cells, such as PTK7 [148] and c-Met [149] or PD-L1 [150], an immune checkpoint, can be targets of aptamers for binding to cancer cells. Here, PTK7 is linked to cancer.