BTK is activated in monocytes and macrophages in numerous acute inflammatory conditions, including polymicrobial sepsis and cerebral ischaemia (Ito et al., 2015; O'Riordan et al., 2019) but also in chronic inflammatory conditions such as obesity‐induced diabetes, rheumatoid arthritis and lupus (Hartkamp et al., 2015; Honigberg et al., 2010; Purvis et al., 2020). Here, BTK is linked to rheumatoid arthritis.