diff --git a/core/PhysiCell_phenotype.cpp b/core/PhysiCell_phenotype.cpp
index 935054ff5..c9e5680ea 100644
--- a/core/PhysiCell_phenotype.cpp
+++ b/core/PhysiCell_phenotype.cpp
@@ -1279,7 +1279,7 @@ Cell_Interactions::Cell_Interactions()
 	pAttackTarget = NULL; 
 	total_damage_delivered = 0.0; 
 
-	attack_duration = 120.0; // 0.1; // get from cell constants instead?? 
+	attack_duration = 30.0; // a typical attack duration for a T cell using perforin/granzyme is ~30 minutes
 
 	fusion_rates = {0.0};