Cells grown in a 3D micro-environment look and behave more like cells in human tissues than those cultured in 2D. They are in contact with other cells and produce extracellular matrix, which influences tissue-specific gene expression, cell growth and the uptake and metabolism of drugs. 3D cell-based in vitro assays can provide more realistic data on the efficacy of drug candidates against tumour cells or their toxicity, potentially reducing the risk
of failure in expensive clinical trials.