library_construction_protocol: To generate the single cell suspension, cells were washed with 1X PBS and treated with 0.25% Trypsin EDTA for 5 minutes. The cells were then washed 3 times with 1X PBS + 0.04% BSA and resuspended in 1X PBS + 0.04% BSA at approximately 1 x 106 cells/mL. Single cell capturing and cDNA library generation were performed by the Bauer core facility at Harvard University using the 10X Chromium 3' library construction kit v2 following the manufacturer's instruction. The library was sequenced (paired-end, 150 cycles) using two NextSeq High Output flow cells (Illumina). Other: single-cell RNA-Seq