THY1 and neoplasm: One of these mechanistic studies by Yu et al. which evaluated the effect of TAF secreted periostin (POSTN) on HNC, and found that HNC tumor cells treated with POSTN showed increased expression of stem cell markers including CD166, SALL4, CD271, CD90, CD133, OCT-4, ALDH, SOX2, and NANOG as well as increased spheroid formation (Yu et al., 2018).