Herpes simplex virus type 1 (HSV-1) is a well-established model to investigate virus-host interactions due to its ability to modulate cell fate and establish lifelong persistence. Among the immediate-early genes, the multifunctional regulatory protein ICP27, encoded by the UL54 gene, plays a central role in viral mRNA processing, nuclear export, and reprogramming host gene expression. This study investigates the role of ICP27 in modulating the intrinsic apoptotic pathway in two cell models repre