heterochromatin formation obsolete senescence-associated heterochromatin focus assembly https://github.com/geneontology/go-ontology/issues/22024 true GO:0035986 OBSOLETE. The assembly of chromatin into senescence-associated heterochromatin foci (SAHF), transcriptionally-silent heterochromatin structures present in senescent cells, containing the condensed chromatin of one chromosome, and enriched for histone modifications. Formation of these chromatin structures is thought to repress expression of proliferation-promoting genes. 2011-08-25T04:43:56Z biological_process SAHF formation senescence-associated heterochromatin foci formation bf senescence-associated heterochromatin focus formation This term was obsoleted because there is no evidence that this is a distinct process; this should be captured as an extension.