obsolete DNA damage response, signal transduction by p53 class mediator resulting in transcription of p21 class mediator https://github.com/geneontology/go-ontology/issues/26003 true OBSOLETE. A cascade of processes induced by the cell cycle regulator phosphoprotein p53, or an equivalent protein, resulting in the induction of the transcription of p21 (also known as WAF1, CIP1 and SDI1) or any equivalent protein, in response to the detection of DNA damage. The reason for obsoletion is that this term is about down stream effects, not the signaling pathway itself. GO:0006978 biological_process DNA damage response, signal transduction by p53 class mediator