FOXD4 and head and neck cancer: We further analyzed the transcriptional profile of FOXD1, FOXD2 and FOXD4 in the anatomic subdivision of TCGA head and neck cancer (Figure S1A) and found that the expression of FOXD2 in the hypopharynx and FOXD4 in the tonsil is relatively higher than other tissues, such as the oral cavity (Figure S1B).