The article focuses on low-quantity gene expression (LQ-DGE) and chromatin immunoprecipitation combined with high-throughput sequencing (ChIP-seq), the two methods that describe gene expression and chromatin profiling of small cell numbers. It states that LQ-DGE permits the characterization of messenger RNA (mRNA) profiles of small cell numbers without an amplification step. It adds that ChIP-seq depends on the amount of protein being targeted and the quality of the antibody.