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). Here, COL4A2 is linked to ovarian cancer.