Even if both NTRK1 and p75NTR were present in the tumor cell nests, they were mutually exclusive, meaning that NTRK1+ and p75NTR+ cells are two separate cell populations of the HNSCC tumor cell nests; moreover, this finding could be extended to cultured cell lines, as revealed on Figure 6. Here, NTRK1 is linked to head and neck squamous cell carcinoma.