This has been observed in stem cells from exfoliated deciduous teeth (SHED cells) from FOP patients, where inflammatory triggers activate the TLR3/TLR4 receptor, further stimulating the BMP signaling through the ECSIT adaptor, which links TLR signaling to the SMAD1/5/8 phosphorylation cascade [71]. The gene discussed is SMAD1; the disease is fibrodysplasia ossificans progressiva.