TBX21 and infection: A subset similar to the actBC2 subset has been described in a range of infections, including in SARS‐CoV‐2,23 influenza25 and other viral infections,24 characterized mainly by gene expression of TBX21 (T‐bet), FAS (CD95) and ITGAX (CD11c) and reported as being similar to an effector B cell phenotype prone to differentiating into antibody‐secreting cells.25, 37, 38