MCC tumor IDs z1369, z1538, z1632 (run 1)
A library preparation process was performed for scRNAseq using the 5 transcriptome kit with feature barcoding (V1.1; 10x Genomics) per manufacturer guidelines. The DNA library was enriched for 1056 human immunology panel genes (10X immunity enrichment kit) and sequenced using a NovaSeq instrument (Illumina) with 2  92 bp paired-end reads. The sequencing aimed to obtain an average of 20,000 reads/cell, following the 10x Genomics guidelines.