SPRR3 and head and neck squamous cell carcinoma: Pyrosequencing was performed on a subset of samples tested by the Infinium MethylationEPIC BeadChip array (Illumina) for four gene promoters, namely SPRR3, FBXO2 (hypermethylated in HNSCC tissue vs. control healthy tissue; Table 1), TRDC and LAIR2 (hypomethylated in HNSCC tissue vs. control healthy tissue; Table 2) tested on four cancer samples and four control samples, each.