This paper Fig2b
b Changes of chromatin accessibility in AMD (n = 14) relative to normal (n = 11) in all retina samples. Each dot represents one ATAC-Seq peak. Blue line in the left panel indicates average fold changes of peaks with the same ATAC-Seq intensity. The percentage of reduced peaks is shown under the density curve in the right panel.
How is the density calculated or what is being shown there? average ATAC seq signal or Fold change?