immune cells, histiocytes, and tumor cells) through the endolysosomal pathway. First, endocytosis of the cell membrane leads to formation of early endosomes, which fuse to form multivesicular bodies; then, the endocytosis of multivesicular bodies form exosomes secreted into extracellular space. [2] It has been reported that exosomes level in plasma of tumor patients is generally higher than that of healthy individuals and is closely associated with the type and progression of tumor. [3][4][5][6] Further studies have shown that exosomes carry multiple biological molecules, such as lipids, proteins and RNAs, which mirror the characteristics of source cells. [7] Therefore, tumor-derived exosomes are being recognized as potential cancer monitors in circulating liquids. As consensus on specific extracellular vesicle markers have not been reached yet, we took sEVs as a replacement term of exosomes in the follow-up paragraphs, in accordance with the MISEV2018 recommendations. [8] Pan-cancer screening is an approach to achieving universe cancer detection simultaneously from a single test, driven by biology and epidemiology. [9] As it would early detect the multiple cancer with pre-symptomy, pan-cancer screening contributes to decreasing the mortality rate of cancers, especially for the cancers without standard of care (SOC) screening method. And compared with a particular cancer type detection, it could increase the diagnostic efficiency for tumors derived from diverse organs. [10] But in liquid biopsy, sEVs are generally emerging as a diagnostics test for a particular cancer type and few applied in multiple cancer screening, which mainly focus on proteins and RNAs carried by sEVs. [11][12][13][14][15][16] Hence, there remains to be researched on lipids carried by sEVs in pan-cancer screening.Phosphatidylserine (PS) is an anionic lipid that is present in intracellular membranes in normal cells. However, in the tumor microenvironment, PS is affected by the influx of calcium ions, [17] flippase inactivation, [18] oxidative stress, [19] and radiochemotherapy, [20] resulting in abnormal flipping of PS to the outside of tumor cell membranes, such as in the non-small cell lung cancer cell lines A549 and H1975, pancreatic cancer cell line MIA PaCa-2, colorectal cancer cell line HT-29, and breast Thanks to containing tumor-related molecules, small extracellular vesicles (sEVs) are emerging as biomarkers in tumor liquid biopsy and commonly employed to diagnose a specific cancer. However, a pan-cancer screening method for pre-symptomatic patients is crucial to achieving the early cancer detection. Herein, a lipid-protein capture system on herringbone (HB) microfluidic chip ( HB EV-Chips) to isolate multiple tumor-derived sEVs is constructed. Phosphatidylserine (PS) is abnormally surface-supposed on tumor-derived sEVs and binds T-cell immunoglobulin domain and mucin domain-containing protein 4 (Tim4) in calcium-dependent manner. PS + sEVs isolated by the HB EV-Chips is perform on liquid chromatography electrospray ionization tandem...