Table 1.

Overview of different types of omics to study trained immunity

Omics type	Technology	Reference
Genomics	DNA microarray	[31]
	DNA-sequencing	[32]
Epigenomics	DNA methylation	[38]
	Chromatin immunoprecipitation (ChIP)-sequencing	[39]
	Assessment of accessible regions (e.g. using DNase-sequencing or ATAC-sequencing)	[40,41]
Transcriptomics	Microarray	[51]
	RNA-sequencing	[51]
Proteomics	Mass spectrometry (MS)	[58]
	Immunoaffinity (antibody-based) assay	[59]
Metabolomics	Nuclear magnetic resonance (NMR)	[60,61]
	Mass spectrometry (MS)	[60]
Microbiome	16S rRNA sequencing	[67]
	Shotgun metagenomic sequencing	[68]
Cell subsets	Flow cytometry	[69]
	Mass cytometry	[70]
Immune functions	Ex-vivo stimulation of immune cells	[71,79]
	Killing assay	[90]
	Clinical phenotype upon infection	[74]