ACTB and lung carcinoma: Although single-cell sequencing sometimes can be criticized as low throughput27 and fewer raw reads can be mapped to the reference genome compared with conventional RNA-seq results (Wilcoxon-rank test, p-value < 2.2e−16 and Supplementary Table 6, using the housekeeping gene ACTB in lung cancer as an example), it provides direct evidence of RNA molecules inside a single cell.