A cancer cell's behavior heavily depends on its immediate neighbors, but it is not known how different patterns of immune and stromal cell infiltrates are set up, nor how stable they may be. A comprehensive histological look at over 100 lung cancer tumors revealed four major subtypes of tumors, based on which immune cells reside in the tumors. The worst outcomes were associated with the plasma cell subtype, which seems to be sustained by APRIL-expressing myeloid cells. Artwork by Lewis Long is based on Fig. 5H in the article by Kurebayashi and colleagues that starts on p. 234 of this issue of Cancer Immunology Research.