(A) Assays focused on in this review: single cell RNA sequencing (scRNA-seq), single nucleus RNA sequencing (snRNA-seq), single-cell sequencing Assay for Transposase-Accessible Chromatin (scATAC-seq), and single cell Spatial Transcriptomics (scST). (B) Other single cell assays: single cell DNA sequencing (scDNA-seq), Cytometry by Time of Flight (CyTOF), Time-Resolved Assessment of Protein Secretion from single cells by sequencing (TRAPS-seq), single cell T Cell Receptor sequencing (scTCR-seq), Transcript-indexed ATAC-seq (T-ATAC-seq), Cellular Indexing of Transcriptomes and Epitopes (CITE-seq), single cell Cap And Tail sequencing (scCAT-seq) and their read-outs.