Timeline of the development of microfluidics-based liver-on-a-chip (LOC) technology. Evolution of the field from the early concept of endothelial barrier-like micropillar by Lee et al. in 2007 to the more complex multi-purpose LOC for drug efficacy study reported by Chen et al. in 2021. Reproduced with permission from [Copyright permissions: 1998—Reproduced with permission from Duff et al., Anal. Chem. 70(23), 4974–4984 (1998). Copyright 1998, American Chemical Society. 2007—Reproduced with permission from Lee et al., Biotechnol. Bioeng. 97(5), 1340–1346 (2007). Copyright 2007 Wiley Periodicals, Inc. 2011—Reproduced with permission from Nakao et al., Biomicrofluidics 5(2), 022212 (2011). Copyright 2011 AIP Publishing LLC. 2013—Reproduced with permission from Lee et al., Enzyme Microb. Technol. 53(3), 159–164 (2013). Copyright 2013 Elsevier Inc. 2013—Reproduced with permission from Lee et al., Lab Chip 13(18), 3529–3537 (2013).Copyright 2013 the Royal Society of Chemistry. 2015—Reproduced with permission from Kang et al., Biotechnol. Bioeng. 112(12), 2571–2582 (2015). Copyright 2015 Wiley Periodicals, Inc. 2016—Reproduced with permission from Bhise et al., Biofabrication 8(1), 014101 (2016). Copyright 2016 IOP Publishing Ltd. 2017—Reproduced with permission from Weng et al., Adv. Mater. 29(36), 1701545 (2017). Copyright 2017 John Wiley & Sons. 2021—Reproduced with permission from Chen et al., Biochem. Eng. J. 165, 107831 (2021). Copyright 2021 Elsevier B.V.].