Overexpression of PTK7 in acute lymphoblastic leukemia(ALL) iscorrelated with an increased resistance to apoptosis, making PTK7a biomarker for cancer detection.37 Toshowcase covalent aptamers as potential tools for cancer diagnostics,we performed labeling experiments in cell lines that endogenouslyexpress PTK7. The gene discussed is PTK7; the disease is acute lymphoblastic leukemia.