Fig. 2

CRISPR-gRNA library screening for upstream regulators of Procr. a Procr⁺ cells were sorted by FACS and expanded by serial passage. In third passage, a population with high Procr expression emerged. b Western blot analysis confirming high Procr protein level in FACS isolated Procr⁺ cells. c RT-qPCR analysis showing similar Procr mRNA transcription level between FACS isolated Procr⁻ and Procr⁺ cells. d The genomic DNA of FACS isolated Procr⁺ cells were extracted and gRNAs which were integrated in the genome were sequenced. Five regulatory gene candidates were identified