FAS and autoimmune lymphoproliferative syndrome: Accessory criteria for ALPS were subdivided into primary (abnormal lymphocyte apoptosis assay and presence of pathogenic mutations in genes of the FAS pathway) and secondary criteria, which included characteristic histopathology, the combined presence of autoimmune cytopenia, polyclonal hypergamma-globulinemia, an ALPS-compatible family history, and the presence of elevated biomarkers, such as interleukin-10, interleukin-18, soluble FAS ligand, and vitamin B12 (Oliveira et al., 2010).