Based on the difference in α-SMA expression levels, CAF-S1 can be further divided into myCAFs and iCAFs subpopulations: myCAFs exhibit high α-SMA expression and are spatially adjacent to tumor cells, while iCAFs have low α-SMA expression and are spatially distant from tumor cells, secreting large amounts of inflammatory factors such as IL-6 [72]. This evidence concerns the gene ACTA1 and neoplasm.