Although, in ALS mouse models, MCP1 is present early in disease prior to microglial activation in the spinal cord [26], the role of MCP1-expressing microglia in recruitment of MCP1 receptor CCR2+ (CC chemokine receptor 2) monocytes to the spinal cord in hSOD1G93A mice remains controversial [27, 28]. Here, CCL2 is linked to amyotrophic lateral sclerosis.