CD33 and neoplasm: Moreover, IHC analysis revealed a borderline significant difference in the proportion of myeloid CD33+ cells in the tumor subgroups (Fisher's exact test; P = 0.092; Fig. 4B), with the ECM3+/IFN− subgroup comprising the lowest fraction of HGBCs classified in the CD33 low category, as well as the highest fraction of samples that did not express activation markers (such as PD‐1; Fig. 4C).