A decade of molecular cell atlases

In recent years there has been tremendous progress towards deep molecular characterization of cell types using single-cell transcriptome sequencing, creating so-called 'cell atlases'. These atlases provide a basic understanding of how different cell types of the same organism - which all share the genome - make distinct use of subsets of genes from the genome to create a variety of distinct cell types across tissues with specialized functions. In this opinion article I discuss some of the history and technological innovations that led to the development of whole-organism atlases.