As an example of pDCs associated with improved outcomes in cancer patients, an immunostimulatory pDC subset that expresses high levels of OX40 (OX40+ pDCs) and lacks ICOS-L expression was recently identified in the TME of head and neck squamous cell carcinomas (HNSCC), especially in patients with HPV+ HNSCC [33]. This evidence concerns the gene ICOSLG and head and neck squamous cell carcinoma.