Following the pseudotime of fibroblasts from Fs0 to Fs1 (Fig. 2F) or from normal scars to keloids (Fig. 2G), the gene expression levels of APCDD1 (a papillary dermal fibroblast marker) and CCL19 (a pro-inflammatory marker) were observed in the beginning and were seen to decrease gradually thereafter. This evidence concerns the gene APCDD1 and keloid.