NTRK1 and breast cancer: We recently developed a chimeric aptamer, axl-miR-214sponge, including an oligonucleotide sequence able to inhibit miR-214 (miR-214sponge) linked to GL21.T (axl), an aptamer that binds specifically to axl, an oncogenic tyrosine kinase receptor abundantly expressed on various malignant melanoma and breast cancer cells.