A subnetwork consisting of a series of transcription factors, such as HOXC13, MSX2, LEF1, DLX3, and FOXN1, and keratins including KRT32, KRT35, and KRT82, that were involved in HFs development, were presented in the PPI network (Figure 4a), which further indicates that these key genes may interact synergistically, promoting the hair growth. Here, KRT32 is linked to Hand-foot syndrome.