The one manipulation that partially decreased regeneration was suppression of CCR2+ monocyte infiltration, suggesting that these cells do contribute, either directly or indirectly, to the effects of cLI on regeneration and that there may be a subset of pro-regenerative CCR2+ monocyte/macrophages related to those involved in the preconditioning peripheral nerve injury phenomenon (20). Here, CCR2 is linked to peripheral nerve injury.