TNFRSF1A and sarcomatoid carcinoma: We failed to detect E-cadherin, a cellular marker that is expressed on the surface of well-differentiated SCCs [31], in the spindle cell carcinomas generated by KALLU+ cells (Fig. 3f); however, E-cadherin expression was detected on the surface of the well-differentiated SCC cells generated by si-TNFR1 KALLU+ cells (Fig. 3f).