Cytokines and chemokines are signaling molecules that play key roles in microglial activation and proliferation. For example: - Interleukin-1 (IL-1) and Tumor Necrosis Factor-alpha (TNF-α) are pro-inflammatory cytokines that can promote microglial proliferation. - Colony-Stimulating Factor 1 (CSF1) and its receptor CSF1R are crucial for microglial survival and proliferation.