Also, as in the case of TB patients, an unusually high number of genes coding for immunoglobulin chains (41 in total) were up-regulated in the TB-like subgroup, along with other genes related to the effector function of B cells (MZB1, JCHAIN) and immunoglobulin receptors (FCGR1A and FCGR1B). The gene discussed is JCHAIN; the disease is tuberculosis.