Variant annotation in particular is one of the key aspects that should be considered when analysing bioactivity data . The same compound can have a very different bioactivity on different genetic variants of the same protein . In fact, some compounds are explicitly designed to have differential bioactivity across variants to, for example, reduce side effects by avoiding targeting the wild-type (WT) protein in anti-cancer therapies, or to target escape variants in antibiotics or antivirals . However, variant annotation tends to be overlooked in bioactivity databases where, in many cases, it is not present or lacks validation. Moreover, even when variants are annotated -as is the case in the ChEMBL database -they are often ignored when constructing a bioactivity dataset, which only recently has been explicitly described as a potential source of noise . The advantage of modelling variant-annotated data has been demonstrated in variant-rich organisms, such as HIV , and the implications in human proteins could be similarly important.