library_construction_protocol: Thymuses were isolated from mice and mechanically dissociated into single-cell suspensions. The dissociated cells were filtered through a 40 µm cell strainer using PBS to remove debris. Red blood cells (RBCs) were lysed using an RBC lysis buffer, followed by washing with PBS. The remaining cells were then resuspended in PBS containing 1 mM EDTA and 2% FBS to maintain cell viability and prevent aggregation. Single-cell RNA sequencing (scRNA-seq) libraries were generated using the 10x Genomics Chromium platform according to the manufacturer's protocol. Library preparation was performed using the Chromium Next GEM Single Cell 3ʹ Kit. The resulting cDNA libraries were amplified and sequenced on an Illumina HiSeq 2000 platform, generating paired-end reads.