NCK1 and infection: In contrast, in a similar manner to TccP-expressing EPEC O119 : H6 strain ICC199 and EHEC O157 : H7 strain EDL933, TccP2-expressing B171 was able to trigger actin polymerization during infection of an Nck1−/Nck2− fibroblast cell line, at a similar efficiency as during infection of an Nck1+/Nck2+ fibroblast cell line (Fig. 3b).