It is also noticed that the origins of high COL1A1, COL1A2, and COL3A1 expression positively correlate with fibroblast-specific markers (FAP) and smooth muscle actin (ACTA2) (Figure 1—figure supplement 1C), whereas COL4A1, COL4A2, and COL18A1 seem to be predominantly expressed in ovarian cancer cells (Figure 1—figure supplement 2). This evidence concerns the gene COL4A2 and ovarian carcinoma.