BEST1 and neoplasm: As shown in Fig. S3, expression of the top 15 genes upregulated in attached OCMI cells (identified above) was also increased in tumor tissue relative to spheroids, including CALB2 and PDPN. It is unlikely that the higher expression of mesothelial and mesenchymal genes in tumor tissue originates from host cells, since the immune cell markers CD4, FCGR3A (CD16), CD14, and CD163 and the mesothelial markers BEST1 and HSPG2 are expressed at similar levels in spheroids and tumor tissue (Fig. S3).