obsolete suppression by virus of host JAK1 activity by negative regulation of JAK1 phosphorylation true GO:0039577 bf The reason for obsoleting this term is that it is too specific. The exact molecular roles of the individual proteins should be captured separately. biological_process OBSOLETE. Any process in which a virus stops, prevents, or reduces the frequency, rate or extent of host JAK1 (Janus Kinase 1) activity by stopping, preventing or reducing tyrosine phosphorylation of JAK1 and thereby activation of JAK1.