CX3CR1 and ischemia: In models of permanent ischemia, the question of how monocyte‐derived macrophages reach the unperfused ischemic core remains little explored.[41] Our data, showing for the first time to our knowledge the presence of circulating CX3CR1‐GFP/+ cells in the ischemic heart, suggests that their entry route might be via retrograde collateral pial blood flow.