Elevated levels of PD-L1 have been identified in ACP cyst cavity linings which correlates with Epidermal Growth Factor Receptor (EGFR) activation in ACP (107), providing rationale for the use of immune checkpoint inhibitors (ICI) through effects on EGFR and MAPK/ERK pathways inhibiting tumor growth (106, 107). The gene discussed is EGFR; the disease is cyst.