ACP3 and viral infectious disease: Building on the findings of mouse models, two classes of amyloids with divergent primary sequence, but similar biochemical properties, have been isolated from human semen, namely: prostatic acid phosphatase peptides (PAP, also known as Semen-derived Enhancer of Viral Infection or SEVI (Munch et al., 2007; Lee and Ramamoorthy, 2018)) and semenogelin (SEM) amyloid (Roan et al., 2017).