Summary of microfluidic publications concerning cell interaction/migration studies in I/O. Legend: Ab: antibody, BCG: Bacillus Calmette–Guérin, CAR-T: chimeric antigen receptor T cells, DC: dendritic cell, FPR1: frizzled-related protein, EMT: epithelial–mesenchymal transition, ICB: immune checkpoint blockade, IT: immunotherapy, NK: natural killer cells, NP: nanoparticle, PBMC: peripheral blood mononuclear cells, PDMS: polydimethylsiloxane, TCR: T cell receptor.

Author	Topic	IT type	Model	Chip material	2D/3D	Static/perfusion	Chip layout
Hsu et al., 2012 (ref. 33)	Interactions between human lung cancer cells, macrophages and myofibroblasts	General cell interactions/migration	Cell lines	PDMS	2D	Pneumatic conduits and microvalves allowed control over conditioned medium available to each cell type	Three cell culture chambers connected by y-shaped channel designed so all angles were at 120° to allow for symmetrical distribution of conditioned media
Businaro et al., 2013 (ref. 34)	Role of IRF-8 in communications between cancer and immune cells	General cell interactions/migration	Mixed	PDMS	3D	Static – manual pipetting	Three cell culture chambers connected by an array of microchannels to permit chemical and physical contact amongst the two cell types
Agliari et al., 2014 (ref. 35)	Benefit of integrating microfluidics with mathematical models to fully quantify experimental image data of real-time interactions between cells	General cell interactions/migration	Mixed	PDMS	3D	Static – manual pipetting	Three cell culture chambers connected by an array of microchannels to permit chemical and physical contact amongst the two cell types
Mattei et al., 2014 (ref. 36)	Role of IRF-8 in communications between cancer and immune cells	General cell interactions/migration	Mixed	PDMS	3D	Static – manual pipetting	Three cell culture chambers connected by an array of microchannels to permit chemical and physical contact amongst the two cell types
Bai et al., 2015 (ref. 37)	Effect of different macrophage subtypes on tumour aggregate dispersion (mimicking EMT)	General cell interactions/migration	Mixed	PDMS	3D	Static – manual pipetting	Four cell culture chambers connected by an array of microchannels to permit chemical and physical contact amongst multiple cell types and allowing hydrogel formation
Zhao et al., 2015 (ref. 38)	Role of lactate on macrophage recruitment by and cytotoxicity against cancer cells (relevant to BCG vaccine immunotherapy)	General cell interactions/migration	Cell lines	PDMS	3D	Static – manual pipetting	Four culture chambers with one media channel, each of which could house a different cell type. One matrigel channel and seven migration channels lay between each adjacent culture chamber with each chamber having its own media channel
Liu et al., 2015 (ref. 39)	Sensitivity of cancer cells to six different chemotherapy regimes	General cell interactions/migration	Cell lines	PDMS	3D	Microscale vacuum suction apparatus	Culture channels interconnected by microchannels to allow exchange of soluble biological factors and metabolites between cell types. Four cell culture areas connected to a central pool through microchannels which functioned to provide a pressure balance during matrigel perfusion
Vacchelli et al., 2015 (ref. 40)	Effect of FPR1 expression on DC response to cancer cells after chemotherapy treatment	General cell interactions/migration	Mixed	PDMS	3D	Static – manual pipetting	Three cell culture chambers connected by an array of microchannels to permit chemical and physical contact amongst the two cell types
Biselli et al., 2017 (ref. 41)	Interactions between human breast and colon cancer cells and human PBMC	General cell interactions/migration	Mixed	PDMS	3D	Static – manual pipetting	Three cell culture chambers connected by an array of microchannels to permit chemical and physical contact amongst the two cell types
Lucarini et al., 2017 (ref. 42)	Effect of the drug decitabine (DAC) in enhancing anti-tumour effects of IFN through immune cell recruitment to the tumour site	General cell interactions/migration	Mixed	PDMS	3D	Static – manual pipetting	Three cell culture chambers connected by an array of microchannels to permit chemical and physical contact amongst the two cell types
Chen et al., 2018 (ref. 43)	Role of inflamed neutrophils in promoting cancer cell metastasis under perfusion conditions	General cell interactions/migration	Mixed	PDMS	3D	Perfusion of vascular network – manual pipetting	Formation of 8 independent vascular beds with a single gel injection port connected by a branching network. Each sub-unit consisted of 4 parallel channels
Boussommier-Calleja et al., 2019 (ref. 44)	Migration and development of various subsets of monocytes and monocyte-derived macrophages as targets for anti-metastatic immunotherapies and their effect on cancer cell extravasation	General cell interactions/migration	Cell lines	PDMS	3D	Perfusion of vascular network – manual pipetting	Three parallel channels where monocytes can be observed over a 5 day period migrating through an endothelial barrier to interact with fibroblasts in a central hydrogel channel
Lei et al., 2020 (ref. 45)	Interactions between cancer and immune cells involved in tumour escape from immune surveillance	General cell interactions/migration	Mixed	Paper layer on top of PMMA layer	3D	Static – manual pipetting	Paper layer containing 5 microreactors on top of a PMMA layer with hydrogel diffusion channels