To evaluate the effect of a more “chronic” exposure to TGF-β1, mimicking the preeclampsia process, and to decipher whether p38 MAPK may be involved in Nox activation, we monitored the enzyme activity in first trimester chorionic villi treated with 10 ng/mL TGF-β1 for 48 h with or without pretreatment with 10 μM SB203580 (a p38 MAPK inhibitor referred as SB) for 1 h. Here, TGFB1 is linked to preeclampsia.