SNAI1 and neoplasm: Based on accumulating data, macrophages promote metastasis in the tumor microenvironment [30] and release pro-inflammatory cytokines, including interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α), to initiate inflammatory responses and subsequently induce tumor migration and invasion by promoting EMT through the regulation of transcription factors, such as Snail, Slug and Twist [31,32,33].