M2 macrophage increased MCL growth via STAT1 signaling. STAT1, STAT3, ERK, and p65 phosphorylation in Granta (A) and Mino (B) cells was measured after direct or indirect coculturing with THP-1-Mφ with or without IL-10 neutralizing antibody. (C) Immunofluorescence staining showing CD19 and p-STAT1 staining in the Mino or Mino + CD14 inoculated MCL xenograft tumors (n = 3). (D) Cell proliferation in Mino and Granta was measured by MTT assay after coculturing with THP-1-Mφ with or without IL-10 neutralizing antibody. Cell proliferation in Mino and Granta was measured by MTT assay after direct or indirect coculturing with THP-1-Mφ with or without STAT1 and STAT3 inhibitor (E) or STAT1 and STAT3 shRNA (F). Data are presented as mean ± standard deviation from 3 separate experiments. *P < .05. GAPDH, glyceraldehyde-3-phosphate dehydrogenase.