dbSearch Help tips:

Search results are obtained by scanning two database tables for the matching information: experimental entries and targeting entries. When searching for the query conditions, if the fields in either table do not match the conditions, the pair of experiment and targeting information for a given ORF will not be displayed.

By explicitly entering an "Experiment Date" to search for, database entries that do not have an entry with an experiment date will not be returned (as blank entries cannot be compared with a logical operator). An example would be if an entry for an ORF has targeting info, but no experimental info. If you wish to ensure that all appropriate targeting and experiment results are returned, please leave the "Experiment Date" field blank in your search.

The same logic applies to the "Stage" and "Status" fields.