library_construction_protocol: A total of eight samples, including both pre- and post-transplantation samples (N=4), were utilized. Following careful thawing of the PBMCs, eight distinct cell multiplexing oligos were applied for demultiplexing. Single-cell capturing and library construction for scRNA-seq analysis were conducted according to the manufacturer's instructions (10X Genomics, Pleasanton, CA; Chromium Next GEM Single Cell 3' HT Reagent Kits v3.1, CG000419). PBMC samples and gel beads were combined on the Chromium Next GEM Chip M to produce gel bead-in-emulsions (GEMs). During the polymerase chain reaction (PCR), complementary DNA (cDNA) from poly-adenylated mRNA and DNA from cell multiplexing oligos were synthesized simultaneously. The resulting full-length cDNA underwent a cleanup process with a Cleanup Mix solution containing Dynabeads MyOne SILANE (PN 2000048, 10X Genomics) for each sample. Post-cleanup, cDNA was amplified to create libraries for gene expression and cell multiplexing oligo libraries.