MPPE1 and cancer: Stabilization of β-catenin in melanoma or liver cancer impedes the production of the cDC1-recruiting CCL4 or CCL5, causing a lack of cDC1 infiltrates within the TME.3 14 Also, some tumors express the enzymatic machinery to synthetize PGE2, which strongly inhibits NK cell-mediated recruitment of cDC1 into the TME.4 15 Efforts to develop efficient strategies to use cDC1s in cancer immunotherapy are being pursued.16