IL2RA and head and neck squamous cell carcinoma: IL-2R is expressed on non-hematopoietic cells, especially on several types of tumor cells like melanoma [10], human squamous cell carcinoma of the head and neck (SCCHN) and keratinocytes [11], epithelial cells [12], and cervical cancer cell lines (HeLa and INBL, HPV-18+) [21].