{"entity":{"id":"microarray-expression","kind":"term","name":"Microarray expression data","aka":["microarray expression","expression microarray","expression microarrays","microarray data","Affymetrix array","Illumina expression array","hybridisation platform"],"tldr":"Microarrays measured gene expression by hybridising labelled RNA to spots of known DNA on a chip; they preceded RNA sequencing and still hold the longest-followed cohorts.","summary":"A DNA microarray is a collection of microscopic DNA spots on a solid surface used to measure the expression of large numbers of genes at once (Wikipedia). The METABRIC breast cancer cohort of about two thousand patients with long follow-up is microarray based, which makes it the standard external test for TCGA-trained RNA-seq survival models and a stern one: intensities and read counts have different distributions, so a model must be rank- or quantile-normalised to cross platforms.","asOf":"2026-09-24","wikipedia":"https://en.wikipedia.org/wiki/DNA_microarray","links":[{"label":"Curtis et al., METABRIC: the genomic and transcriptomic architecture of 2,000 breast tumours (Nature 2012)","url":"https://doi.org/10.1038/nature10983"},{"label":"Wikipedia","url":"https://en.wikipedia.org/wiki/DNA_microarray"}],"tags":["cansim-terms"],"related":["cancer-ai-vocabulary"],"cancers":[],"sections":[],"technologies":[],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":["bulk-rna-seq","batch-effects","quantile-normalisation","external-validation"],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":["Listed in the CanSim terms map 1.0.0 (docs/onco/terms.json, generated 2026-09-24), CC BY 4.0, attribution: CanSim project, an open, public-data-first cancer foundation-model programme; CanSim page path /terms/microarray-expression."],"provenance":{"editedBy":"OnCo CanSim terms wave (Wikipedia summaries, standards and project pages, GDC and FDA pages, Europe PMC)","editedOn":"2026-09-24","note":"CanSim terms map 1.0.0 (docs/onco/terms.json, generated 2026-09-24), CC BY 4.0, attribution: CanSim project, an open, public-data-first cancer foundation-model programme"},"category":"Genomics & genetics"},"route":"/terms/microarray-expression/","neighbours":{"term":[{"id":"batch-effects","kind":"term","name":"Batch effects and harmonisation","route":"/terms/batch-effects/"},{"id":"bulk-rna-seq","kind":"term","name":"Bulk RNA sequencing (RNA-seq) and the full transcriptome","route":"/terms/bulk-rna-seq/"},{"id":"cancer-ai-vocabulary","kind":"term","name":"Cancer AI vocabulary (CanSim terms map)","route":"/terms/cancer-ai-vocabulary/"},{"id":"external-validation","kind":"term","name":"External validation","route":"/terms/external-validation/"},{"id":"quantile-normalisation","kind":"term","name":"Quantile normalisation, rank transforms and z-scores","route":"/terms/quantile-normalisation/"}]}}