While TLR/MyD88 signaling has been shown to be critical for Batf3+ cDC1 cross-presentation to CD8+ T cells, we surprisingly found that MyD88 signaling was dispensable in Itgax-expressing cells for the response to radiation therapy but is instead highly impacted by myeloid MyD88 expression in pancreatic cancer. This evidence concerns the gene MYD88 and familial pancreatic carcinoma.