Visualization of a part of an alignment of (A) two paralogous sequences (the human ABCB4 and ABCB1 protein) and (B) two isoforms (the human ABCB4 protein and its isoform c), representing an ideal case. Positions with matches between the two sequences are indicated by "|", mismatches by "#" and amino acids vs. gap characters by ":". The values of the three features (cf. Methods, section Features) for the full-length sequences compared in panel (A) are (i) sequence similarity 75.76%, (ii) inverse CBIN count 0.0027, (iii) fraction of consecutive matches and mismatches 0.7111. For the full-length sequences compared in panel (B) we have (i) sequence similarity 96.33%, (ii) inverse CBIN count 0.3333, (iii) fraction of consecutive matches and mismatches 0.9969.