SPOCK2 and head and neck squamous cell carcinoma: The results indicated that a total of 206 genes were significantly associated with the survival of the recurrent HNSCC among which, OR2I1P, SPOCK2, CCR5, DPT, CD3E, C2, CD4, VCAM1, CD79A, HLA-DRB1, DOK3, TRBC1, RARRES2, AXL, and IGKV1-16 are the most significant prognostic factors in recurrent HNSCC patients (Figure 5 and Supplementary Table 3).