Systemic application of L. monocytogenes is used in many studies related to host-pathogen interaction [9, 33, 34] , and spleen and liver were defined as the target organs of these bacteria [23] . Little attention has been paid to lymph nodes until now. Our finding that IFN-b is produced in the lymph nodes lead us to test whether lymph nodes are also colonized by Listeria after i.v. infection. Indeed, already 24 hours p.i. we could observe bacteria in cervical and inguinal lymph nodes independent of the bacterial strain used (Fig. 1C) . Between 24 and 48 hours p.i., bacterial burdens in lymph nodes increased about 100 fold. Colony forming units of Listeria in spleens and livers also increased although not as dramatic.