NTRK1 and cancer: In addition, we also found that NGF has the potential to selectively affect the proliferation of breast cancer cells rather than normal breast epithelial cells, so NGF may be the best treatment target for specific cancer types; The effect of NGF on cancer cells varies depending on the expression status of TrkA and/or p75NTR and varies with the use of chemotherapy drugs, and may have a greater impact on immune or drug therapeutic effects (Noh et al., 2017).