Malaria spreads to human hosts via bite of an infected mosquito. Upon bite, the parasite travels to the liver where it grows until it breaks out into the blood 8-9 days later, initiating symptomatic disease. This image shows a liver stage parasite (exoerythrocytic form) in primary human hepatocytes. You can see that the parasite pushes against the nucleus of its host hepatocytes (in blue) to make room for itself inside the cell. In green is the membrane of the parasite (UIS4) and in red is Heat Shock Protein 70 (HSP70).