Among the 14 viruses and 16 bacteria for which 217 and 115 variants were tested, respectively, two organisms concentrated the majority of the data available (Supplementary Table ). HIV-1 accumulated 54.8% of the viral variants and 70.6% of the viral bioactivity data in just five proteins. Similarly, Escherichia coli concentrated 20.9% of the bacterial variants and 42.0% of the bacterial bioactivity data tested in eight proteins. A closer look into the nature of the substitutions reported in these organisms offered some interesting insights when compared to EGFR as a proxy for a human protein with disease-relevant variants. In line with the general observation across human proteins, the nine single substitutions reported for EGFR were few but of high relevance, with only one conservative substitution and Epstein coefficients of difference around (three) or higher than (five) 0.4 (Figure ). Based on the 77 crystal structures available, all reported EGFR substituted amino acids were located from 8Å