Immediately after thoracic resection, tissue-damage-associated molecular patterns trigger a systemic cytokine surge (IL-6, IL-8) and a brief lymphopenia/NK-cell dip that can last several days; this “danger-signal” phase is now recognized as a normal, self-limiting response that resolves more quickly after minimally invasive surgery [25]. Here, CXCL8 is linked to lymphopenia.