Step-by-step roadmap for cancer biomarker selection and subsequent photoacoustic imaging agent design. Reproduced from ref. 120 with permission from Elsevier, Copyright 2017; from ref. 69 with permission of American Chemical Society, Copyright 2017; from ref. 141 with permission from Elsevier, Copyright 2020; from ref. 55 with permission from Royal Society of Chemistry, Copyright 2021; from ref. 79 with permission from American Chemical Society, Copyright 2020; from ref. 377 with permission from John Wiley and Sons, Copyright 2019.