['Ecto-Nucleoside Triphosphate Diphosphohydrolases (Ecto-NTPDases) are enzymes that hydrolyze tri- and/or di-phosphate nucleotides. Evidences point to their participation in Trypanosoma cruzi virulence and infectivity. In this work, we evaluate TcNTPDase-1 gene expression in comparison with ecto-NTPDase activity, in order to study the role of TcNTPDase-1 in parasite virulence, infectivity and adaptation to heat shock.', 'Comparison between distinct T. cruzi isolates (Y, 3663 and 4167 strains, and Dm28c, LL014 and CL-14 clones) showed that TcNTPDase-1 expression was 7.2\u2009±\u20091.5 times higher in the Dm28c than the CL-14 avirulent clone. A remarkable expression increase was also observed in the trypomastigote and amastigote forms (22.5\u2009±\u20095.6 and 16.3\u2009±\u20093.8 times higher than epimastigotes, respectively), indicating that TcNTPDase-1 is overexpressed in T. cruzi infective forms. Moreover, heat shock and long-term cultivation also induced a significant increment on TcNTPDase-1 expression.'] Is nucleoside triphosphate diphosphohydrolase1 ( TcNTPDase-1 ) gene expression increased due to heat shock and in infective forms of Trypanosoma cruzi?