Protein Tyrosine Kinase 7 (PTK7) in Breast Cancer: A Retrospective Analysis of Tumour Expression and Association with Clinical Outcome.

Protein tyrosine kinase 7 (PTK7), originally known as colon carcinoma kinase (CCK4), is an evolutionary conserved, catalytically defective transmembrane receptor involved in Wnt signalling. PTK7 has been identified as a potential therapeutic target, and a PTK7 antibody drug conjugate (PF-06647020; cofetuzumab pelidotin) has been investigated in phase I clinical trials for triple-negative breast cancer, ovarian cancer, and non-small cell lung cancer. PTK7 protein expression was evaluated in 1136 early-stage invasive breast tumours by immunohistochemistry.