NTRK1 and breast carcinoma: Moreover, Islam et al. [14] demonstrated that Russell’s Viper Venom (RVV)-NGFa (an NGF isoform), labelled with Fluorescein Isothiocyanate (FITC), establishes strong binding to TrkA and NGFR/p75NTR receptors in breast cancer cells but not in non-cancerous cells.