library_construction_protocol: mRNAs from sorted single cells were reverse transcribed and amplified as previously described. Library preparation and sequencing were performed as described previously. Sequencing libraries for cDNA from single cells were prepared as per the Single Cell 3′ v2 Reagent Kits User Guide (10x Genomics, Pleasanton, CA, USA). Cellular suspensions were loaded on a Chromium Controller instrument (10x Genomics) to generate single-cell Gel Bead-In-EMulsions (GEMs). GEM-reverse transcription (RT) was performed in a Veriti 96-well thermal cycler (Thermo Fisher Scientific, Waltham, MA, USA). GEMs were collected and the cDNA was amplified and purified with SPRIselect Reagent Kit (Beckman Coulter, Brea, CA, USA). Indexed sequencing libraries were constructed using Chromium Single-Cell 3′ Library Kit for enzymatic fragmentation, end-repair, A-tailing, adapter ligation, ligation cleanup, sample index PCR, and PCR cleanup. The barcoded sequencing libraries were quantified by quantitative PCR using the KAPA Library Quantification Kit for Illumina platforms (KAPA Biosystems, Roche Holding AG, Basel, Switzerland). Sequencing libraries were loaded on a NextSeq500 (Illumina, San Diego, CA, USA) with a custom sequencing setting (26bp for Read 1 and 98bp for Read 2) to obtain a sequencing depth of ~200K reads per cell.