Given the role of CD80 in regulating the immune system is complicated, providing the opportunity for CD80 interactions to be involved in various diseases including multiple autoimmune diseases (Windhagen et al., 1995; Wong et al., 2005; Nolan et al., 2008), and various cancers (Yang et al., 2006; Imade et al., 2013). Here, CD80 is linked to cancer.