PTK7 participates in signaltransduction during the development and metastatic spread of malignant tumors.Moreover, the sgc8  aptamer is capable of penetrating into CCRF-CEMcells, where it localizes in endosomes [29].The C8FL  aptamer containing 33 nucleotides and a linker and possessingexceptional stability to serum nucleases and high affinity to target cells (Kd  = 1.53 nM) was obtained via minimization of the nucleotide sequence ofthe sgc8 aptamer and the introduction of chemical modifications intoits structure ( Fig. 5) [18]. This evidence concerns the gene PTK7 and cancer.