MMP7 and infection: The ventral clumping of mmp7-positive cells in BR– after infection was not detected in SC– and Tail– embryos, resulting in significant differences between BR– and Tail– groups (Bonferroni’s posttest P = 0.0225 for BR– vs. Tail– at ventral area; Fig. 3k), and demonstrating that the effect was not due simply to surgical damage or the need for an intact CNS.