library_construction_protocol: Mouse epithelial cell suspensions were obtained by standard dissociation (refer to Min et al, 2019). Viable cells were enriched with MACS. Cells were encapsulated using the inDrop platform (1CellBio), and RNA was extracted according to the protocol of Klein et al., 2015. CEL-Seq linear amplification of RNA/cDNA followed by index primer-based amplification. RNA-Seq was performed on NextSeq500 with a 2 x 75 paired-end kit using custom read lengths.