NOS2 and neoplasm: To confirm our in vitro and in vivo findings revealing that NOS inhibition reverses EMT and enhances tumor differentiation, we performed immunofluorescence analysis and evaluated the expression of epithelial marker E-cadherin, ZEB1, and ALDH1 in responder and non-responder tumor biopsies at BL and EOT from the L-NMMA+taxane clinical trial discussed in Fig. 1.