INPARANOID is an algorithm which finds orthologous genes and those paralogous genes which arose—most likely by duplication--after some speciation event. Such protein-coding genes are called in-paralogs, as opposed to out-paralogs (which arose prior to the species split).[1]
Inparanoid (with varying capitalization) may refer to the program which utilizes the INPARANOID algorithm as well as the derived database; this database lists orthologous clusters of genes.[2]