B3GNT3 and neoplasm: The third (TMEM3) and fourth (TMEM4) methods quantified TMEM doorway density, as described previously [10], as the sum of TMEM doorways within a given area: namely, the 10 high power fields of view (40× magnification, 330 × 440 μm2) that contained the most TMEM doorways in either the Whole Tumor Tissue ROI (Figure 2E) or the Path ROIs (Figure 2F), respectively.