At Public Health England (PHE), recently established technology allows direct counting of nucleic acid molecules (DNA, mRNA, miRNA and lncRNA) without the need for enzymatic reaction or amplification steps hence reducing time for data collection. The system offers multiplexing capacity comparable to microarrays but with greater precision and sensitivity. Another unique advantage of this technology is that there is no need for long, time consuming bioinformatic analyses as the results are obtained as counted number of events. This new gene expression analysis technique has been assessed for radiation biodosimetry applications with promising results. Furthermore, gene expression has shown a high degree of promise as a marker for late effects of radiation, for instance normal tissue reactions following curative radiotherapy for breast cancer. Clinical data suggest that systemic inflammatory responses plays a critical role in the progression of radiation effects: for instance, the neutrophil-to-lymphocyte ratio represents a marker of systemic inflammation pre-treatment and is an independent prognostic factor useful for individual risk assessment in breast cancer patients undergoing radiotherapy. Genes relevant to inflammatory responses are thus interesting candidates for further investigation. Linearity of the transcriptional dose-response for specific radiation-responsive genes in ex vivo exposed human blood samples has recently been demonstrated for the first time, and inter-individual variability in the response after low doses and high doses exposures has been newly assessed. The logical next stage for biological development of the gene expression assay is to validate these new techniques with human blood samples exposed to radiation in vivo.