Counting coinciding PPI and AS regions. For clarity, no smoothing was made. a. By individual residues. In this example, there are 20 amino acid positions involved both in PPI and AS (PPI/AS, red colour), 19 non-PPI/AS positions (blue colour), 10 PPI/non-AS positions (green colour), and 6 non-PPI/non-AS positions (black colour). b. By entire sequence segments. In this example there are three PPI regions entirely covered by AS regions (red), one PPI region partially overlapping with an AS region (blue), and one PPI region not overlapping with AS.