SUZ12 and breast cancer: To evaluate whether PRC2 loss has a similar effect on the TME in other cancer types, we used CRISPR/Cas9-mediated knockout of the PRC2 core components Eed or Suz12 and generated a PRC2-isogenic murine mammary tumor model (AT3, sgCon vs. sgEed or sgSuz12) amenable for syngeneic transplantation into C57BL/6J mice (Supplemental Figure 6A).