We have previously reported characteristics of biological effects of RF SAR131675 1433953-83-3 exposure on auditory hair cells. Auditory hair cells could easily be exposed to mobile phone frequency and 1,763 MHz RF exposure, but this exposure did not induce cellular responses, including cell cycle distribution, DNA damage, stress response, or gene expression changes at 20 W/kg specific absorption rate in HEI-OCI auditory hair cells. RF ablation provides a controlled heating modality on microscopic tissue targets based on RF electrical current flow. Furthermore, a variety of models have been proposed to explain the mechanism of wound healing by electrical stimulation. Previous studies using high-voltage pulsed galvanic stimulation showed that the electrical stimulus induced cell migration and wound repair through increased protein and DNA synthesis. Maddin et al. demonstrated that a pulsed electrostatic field had positive biological effects on hair re-growth but the biophysical mechanism was not clear. The dermal papilla is a discrete population of specialized fibroblasts and plays a pivotal role in hair formation, growth, and cell cycling. To explore the effect of RF radiation in human hair follicle cells, we irradiated human dermal papilla cells to code division multiple access-type 1,763 MHz RF radiation and monitored alterations at molecular and cellular levels. In ex-vivo organ culture of hair follicles, we measured hair shaft elongation after RF exposure. Our results suggest that RF exposure could stimulate human hair growth in vitro. Various studies have been conducted to determine the biological effects of RF radiation, but it has not yet been determined if RF radiation poses a potential hazard. The biological effect of RF radiation remains controversial and the results from different studies may vary due to different experimental conditions and model systems. In an effort to find cell type-specific responses to RF radiation in our previous study, we tested the effect of 1,763 MHz RF radiation on Jurkat human T cells and HEI-OC1 mouse auditory hair cells using microarray analysis. However, we could not find significant alteration in gene expression and cell signaling. In this study, we examined the effect of RF exposure on primary cultured human HFs and hDPCs to find the increased hair growth of ex vivo cultured HFs through the expression of growth factors such as IGF-1. Hair growth is observable in the anagen stage before the regression phase and the resting phase of the hair follicle cycle. Growth factors are polypeptides that are involved in the regulation of hair morphogenesis, hair cell proliferation, and hair growth. Some reports have provided evidence that growth factors such as VEGF, IGF-1, and HGF have hair growth stimulatory activity, while TGF-b1 has inhibitory effects on hair growth. It has been reported that IGF-1, VEGF, fibroblast growth factor 5, and fibroblast growth factor 7 induce proliferation of cells in the matrix, dermal papilla, and dermal papillary vascular system and increase the amount of extracellular matrix in dermal papilla. These factors also maintain follicles in the anagen phase, whereas TGF-b1 evokes apoptosis of matrix cells and shifts the follicles from anagen to catagen.