Notably, elevated expression levels of production of immunoglobulin-related genes IGHG4, IGKC, IGLC2, IGHG3, and PLAU were detected in the SPP1-Mφ cluster, suggesting the proinflammatory and anti-tumor functions of this cluster in lung cancer (Supplementary Fig. 6a). Here, IGHG4 is linked to lung carcinoma.