The reference cytochrome b protein (UniProt ID: P00163; length: 385 amino acids) from Saccharomyces cerevisiae served as a query sequence for BLAST searching against the proteomes of P. insidiosum (Taxonomy Identifier [TAXID]: 114742) (34, –, 38) and susceptible hosts to pythiosis, such as human (Homo sapiens; TAXID: 9606), horse (Equus caballus; TAXID: 9796), and dog (Canis lupus familiaris; TAXID: 9615). The gene discussed is MT-CYB; the disease is Pythiosis.