Furthermore, although previous studies suggested amphibians lack a robust adaptive immune defense against Bd, immunoglobulins (IgM and IgY) are known to neutralize Bd in vitro (Ramsey et al. 2010; Rollins-Smith et al. 2011), splenocyte abundance may increase with multiple Bd exposures (McMahon et al. 2014), and the complement system may be initiated in early stages of infection (Grogan et al. 2018). This evidence concerns the gene CD40LG and infection.