To further elucidate how the microbial features involved in our RF14 classifier contribute to the development of irAEs, we used an extra study, consisting of 9 melanoma patients who received anti-PD-1/PD-L1 treatment with both fecal 16S rRNA amplicon sequence and bulk RNA sequencing on the normal intestinal or colorectal mucosa available. Here, PDCD1 is linked to melanoma.