The cellularity of AV tissue, especially that of CD14+ and CD16+ monocytes, CD68+ macrophages, and CD42+ platelets, was significantly increased in FP-AS compared with SP-AS (Figure 2A), suggesting an extravasation and infiltration of immune cells into the AV tissue (CD14+/CD16+/CD68+ cells in SP-AS versus FP-AS, respectively, cells/mm2: median [IQR]: 29 [7–67.3] versus 75.5 [36.3–112], P<0.001; 1 [0–6] versus 10 [2–12], P<0.001; 51 [32–76.25] versus 128.5 [75–147.8], P<0.001, respectively; platelet accumulation [CD42b+ area], mm2: 0.78 [0–1.54] versus 1.7 [0.77–2.66]; P<0.001). Here, CD14 is linked to aortic stenosis.