CXCL13 and rheumatoid arthritis: Furthermore, in mouse joints, the expression of RA-specific inflammatory marker genes encoding human IFNγ and TNFα and murine Cxcl13 and Saa1 was increased considerably in NSG-RA mice compared to that in NSG-nonRA mice, as shown by RT-PCR and RNA-seq analysis (Fig. 3) (Vallon et al., 2001; Vinay and Kwon, 2012; Burska et al., 2014; Lu et al., 2014; Armas-González et al., 2018; Bazzazi et al., 2018; Tardito et al., 2019; Zhang et al., 2019; Bechman et al., 2020; Shapiro, 2021).