IGF1 and infection: Following a 24-h in vitro infection, cells were fixed in 4% paraformaldehyde (Sigma), washed in 0·001 m phosphate buffered saline, pH 7·2 (PBS), blocked for 1 h with 2% BSA in PBS, and incubated overnight with monoclonal goat anti-mouse IGF-I antibody (1 : 75; R&D Systems) and a polyclonal mouse anti-Leishmania antibody (1 : 400), which was produced in our laboratory 11.