The presence of CAFs was investigated by using immunostaining with alpha-smooth muscle actin (α-SMA) in a series of 65 formalin-fixed paraffin-embedded (FFPE) tissue sections including thyroid tumors (of different histotypes, details are provided in Table S1) and NTs derived from 48 patients (43 TC patients and 5 NT controls). This evidence concerns the gene ACTA1 and thyroid tumor.