MFAP4 and head and neck squamous cell carcinoma: One sub-state previously not described in HNSCC TME scRNAseq studies were fibroblasts expressing elastic fiber differentiation genes (cluster 7; Supplementary Fig. 6B and Supplementary Data 1), with increased expression of tropoelastin (ELN), fibrillin-1 (FBLN1), and Microfibril Associated Protein 4 (MFAP4)28.