Using a study design similar to the one here, Keil et al. evaluated developmental immunotoxicity in B6C3F1 pups flowing oral maternal exposure to PFOS on Gestational Days 1–17; their results showed that SRBC-specific IgM production was decreased in male pups after exposure to 5.0 mg/kg/day during gestation, but not altered in female pups [31]. This evidence concerns the gene CD40LG and immune system toxicity.