Since we report that neoplastic pTECs in 3D culture maintain the WNT4+FOXN1+ phenotype of TETs much longer than in 2D cultures, we hypothesize that tumor cell–tumor cell and tumor cell–matrix interactions may be important to maintain the autocrine WNT4 loop, FOXN1 expression, and tumor cell survival of TETs in vivo. The gene discussed is WNT4; the disease is neoplasm.