CHIA and cyst: More recently, the use of CellTracker labeled wild type and acidic mammalian chitinase (AMCase)-/- macrophages co-cultured with RFP expressing parasites demonstrated that chitinase secreted by alternatively activated macrophages is responsible for cyst lysis and may be the effector mechanism for the decrease in cyst burden seen in wild type mice over time[42] (Figure 4A).