The study by Konowalchuk, Speirs, and Stavric investigates a novel cytotoxin produced by certain *Escherichia coli* strains, referred to as VT (toxic to Vero cells). This toxin differs from the known heat-stable and heat-labile enterotoxins of *E. coli* and is specifically cytotoxic to Vero cells but not to Y-1 or CHO cells. The toxin is heat-labile and has a molecular weight of 10,000 to 30,000. The researchers tested various *E. coli* strains, including those isolated from diarrhea cases in infants and young pigs, and found that 10 out of 136 strains induced a cytotoxic response in Vero cells. The response was distinct from that of heat-labile enterotoxin (LT), which caused enlarged, thick-walled, and refractile cells with filamentous tendrils. VT was also destroyed by heating at 98°C for 15 minutes and was not cross-neutralized by antiserum against LT. The study suggests that VT may contribute to diarrheal disease in human infants and young pigs, and further research is needed to confirm its role in enteropathogenic diseases.The study by Konowalchuk, Speirs, and Stavric investigates a novel cytotoxin produced by certain *Escherichia coli* strains, referred to as VT (toxic to Vero cells). This toxin differs from the known heat-stable and heat-labile enterotoxins of *E. coli* and is specifically cytotoxic to Vero cells but not to Y-1 or CHO cells. The toxin is heat-labile and has a molecular weight of 10,000 to 30,000. The researchers tested various *E. coli* strains, including those isolated from diarrhea cases in infants and young pigs, and found that 10 out of 136 strains induced a cytotoxic response in Vero cells. The response was distinct from that of heat-labile enterotoxin (LT), which caused enlarged, thick-walled, and refractile cells with filamentous tendrils. VT was also destroyed by heating at 98°C for 15 minutes and was not cross-neutralized by antiserum against LT. The study suggests that VT may contribute to diarrheal disease in human infants and young pigs, and further research is needed to confirm its role in enteropathogenic diseases.