GDF15 and cancer: The assay can detect 105 factors, indicated in Table S3, which shows the pixel density of dots revealed on membranes illustrated in Figure S5A), some of which may contribute to promote cancer growth, cell migration, angiogenesis, and metastasis, such as CXCL5, the urokinase-type plasminogen activator receptor (uPAR), the matrix metalloproteinase 9 (MMP-9), serpin E1 [34], and the growth differentiation factor-15 (GDF-15, a novel targetable immune checkpoint [35]).