Define a subset of the ToxCast database for relevance to toxEval analyses. Subsetting is done based upon methods defined by doi:10.1021/acs.est.7b01613 Blackwell et al., 2017. Specifically, this function removes endPoints that are ATG sources with signal loss, and NVS with signal gain (basically: some assay/signal combinations are removed because they target non-specific endpoints). Also, this function adds additional categories to intended_target_family and intended_target_family_sub as described in the paper linked above.
The returned data frame is based on end_point_info, but with some endPoints filtered out and some additional categories in intended_target_family and intended_target_family_sub. The names in intended_target_family are revised to look more appealing in graphs and tables.