IRF4 and AL amyloidosis: IRF4 is a key regulator at multiple steps in B-cell differentiation and development (Klein et al., 2006; Ochiai et al., 2013; Sciammas et al., 2006) and is an oncogene in multiple myeloma (Shaffer et al., 2009), to a lesser degree in Hodgkin and non-Hodgkin lymphomas as well as in chronic lymphocytic leukemia (Boddicker et al., 2015; Shaffer et al., 2008; Shukla et al., 2013).