TNF and infection: Although we demonstrated that Dif, a Drosophila NF-κB essential for the induction of Drs upon systemic infection in adults, was not involved in pinching-induced Drs expression in larvae, we could not rule out the possible involvement of NF-κB in transactivating Drs expression, as we were unable to examine the redundant role of the other NF-κB proteins, Dorsal and Relish, because of the unavailability of viable lines.