The importance of the B cells infiltrating tumors as regulators of lung cancer progression was indicated by Wang et al.33on one hand, by promoting the T cell response and secreting the tumor‐specific antibodies, the tumor infiltrating B lymphocytes could exert anti‐tumor immunity; on the other hand, B cells can also develop into an immunosuppressive phenotype that secretes IL‐10, thereby promoting tumor development. The gene discussed is IL10; the disease is lung cancer.