# Advanced Omics and Radiobiological Tissue Archives: The Future in the Past
## 5 Lessons from Past for Future  
With a rapidly growing number of advanced omics approaches being used in translational research, the need for biological samples is continuously increasing. Big data generated by omics technologies need to be validated for biological plausibility and reproducibility, especially if the findings from in vitro or in vivo models are to be translated to humans. The use of a larger sample size provides additional material for further validation to address the problems of variability and heterogeneity of omics data with adequate statistical power. In the absence of sufficient frozen samples, FFPE samples, with their countless numbers, ease of storage and rich clinical information, can indeed provide the optimal materials for such retrospective analyses. Unfortunately, the use of FFPE samples is not hassle-free. The first problem is that the initial purpose for tissue collections is often not prospectively defined based on the requirements and capacity of future analysis platforms such as omics. In addition, the conditions for tissue collection, processing and storage are not yet uniform across the laboratories. Protocols for isolation, extraction and separation of biomolecules from FFPE samples are not consistently standardised, and storage and sharing of archival materials and related information are not yet optimal. To address these obstacles, the radiation biology biobanking policy and its infrastructure need to be improved. The optimal quality and quantity of FFPE samples must be well foreseen in the main strategy of tissue collection, oriented towards omics analysis. In an optimal platform, the facility and knowledge are already available to establish uniform protocols for tissue collection and processing, monitor storage condition and status and standardise protocols for biomolecule isolation and extraction. It should be borne in mind that the maintaining of the archival tissues as well as the development of cost- and time-effective protocols require a distinct universal institutional collaboration scientifically and economically. To evaluate the quality and quantity of omics data derived from FFPE tissues, several studies performed analysis on paired frozen and FFPE samples [113; 114]. Comparison of frozen and FFPE tissues is a crucial strategy to evaluate extraction methods and ultimately the validity of FFPE-omics data. Although these studies highlighted the difficulties in FFPE profiling, they were often able to confirm the compatibility, reproducibility, and consistency of FFPE samples for high-throughput omics analyses. Proteomics and transcriptomics analyses have not only demonstrated the applicability of extraction, isolation, and separation of biomolecules from FFPE tissue but have also shown a significant overlap in protein and RNA identification and quantification between FFPE and fresh frozen samples [75; 113; 114]. Unfortunately, such comparisons for radiological FFPE materials have been very limited. One reason for this is that the additional collection of fresh tissue is so time-consuming and costly that it is not a standard part of routine clinical practice in cancer diagnosis and therapy. This is all the more true for samples taken during a radiation disaster, where priorities are still set differently. In the absence of matched frozen samples, FFPE omics derived results need at least to be compared with available data from published studies using similar analytical platforms. An important issue underscores the importance of principles of findability, accessibility, interoperability, and reusability (FAIR) data sharing in the radiation community. Clinical documentation and subsequently general agreementson sharing samples and related data also need to be improved. Standardized data acquisition and data storage, as well as machine-readable output data, will facilitate sharing of metadata and available experimental data. General agreements on how to manage archive material and related data are urgently needed for efficient universal material and data sharing.