Table 2. Example filter types that can be used in ChEMBL web services.

Example	Description	Filter types
https://www.ebi.ac.uk/chembl/api/data/assay?assay_type__exact=B	Exact match with query	exact (iexact)
https://www.ebi.ac.uk/chembl/api/data/assay?description__icontains=toxicity	Wild card search with query	contains (icontains)
https://www.ebi.ac.uk/chembl/api/data/target?pref_name__istartswith=serotonin	Starts with query	startswith (istartswith)
https://www.ebi.ac.uk/chembl/api/data/cell_line?cell_source_tissue__iendswith=carcinoma	Ends with query	endswith (iendswith)
https://www.ebi.ac.uk/chembl/api/data/target?pref_name__iregex=(cdk1|cdk2)	Regular expression query	regex (iregex)
https://www.ebi.ac.uk/chembl/api/data/molecule?molecule_properties__full_mwt__gte=100	Greater than (or equal)	gt (gte)
https://www.ebi.ac.uk/chembl/api/data/molecule?molecule_properties__alogp__lte=5	Less than (or equal)	lt (lte)
https://www.ebi.ac.uk/chembl/api/data/molecule?molecule_properties__full_mwt__range=200,500	Within a range of values	range
https://www.ebi.ac.uk/chembl/api/data/molecule?molecule_chembl_id__in=CHEMBL25,CHEMBL941,CHEMBL1000	Appears within list of query values	in
https://www.ebi.ac.uk/chembl/api/data/assay?assay_tissue__isnull=false	Field is null	isnull

The ‘i’ versions of filter types, e.g. iexact, represent case insensitive forms. The ‘gt’ and ‘lt’ filter_type examples demonstrate how to access a field within a nested block. In these cases the full_mwt and alogp fields are contained within a ‘molecule_properties’ block. To access the fields contained within this section, the field name is double underscore prepended with the outer block name, e.g. ‘molecule_properties__full_mwt’.