The community should look into "neglected or underrepresented chemical spaces" such as metal-containing compounds, food chemicals, and other molecules from natural sources. Systematic computational searches in chemical and biological spaces -virtual screening or target fishingis a common and useful practice in drug discovery with several documented successful cases. To this end, ViSAS is a general approach that expands bioactive molecules' chemical space by finding analogs in libraries of purchasable compounds. The hits can be arranged in an R-group table, similar to a molecule optimization campaign; however, this is probably a first in virtual screening. Although the ViSAS concept is formalized in this review, its principles and applications have been published and discussed. We anticipate that local SAR analysis with ML can help select the most relevant analog series to test experimentally. Similarly, the ViSAS concept can be extended to the analysis of de novo libraries, to focus on novel analog series and identify those that have commercially available precursors.