Salmonella enterica (IMAGE) European Molecular Biology Laboratory Caption When immune cells called macrophages get infected by the intracellular pathogen Salmonella enterica (shown in green), cellular proteins of the cathepsin family (red, indicating cathepsin activity) localise to the nucleus (blue). Credit Joel Selkrig/EMBL Usage Restrictions CC BY-SA 3.0 IGO License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.