One study investigated the modulation of the OGF–OGFr axis by (1) exogenous OGF, (2) upregulation of OGFr using imiquimod, or (3) intermittent opioid receptor blockade with a low dose of NTX on the progression of established squamous cell carcinoma of the head and neck (SCCHN). Here, OGFR is linked to head and neck squamous cell carcinoma.