A fibroblast is a type of cell that synthesizes the extracellular matrix and collagen,[1] the structural framework (stroma) for animal tissues, and plays a critical role in wound healing. Fibroblasts are the most common cells of connective tissue in animals.
For example, a 700 x 20 C road tire would be a 20-622; a 700 x 38 hybrid tire would be a 38-622. The width difference between these sizes would make them less-than ideal replacements for one another, but any rim that could fit one of them would work after a fashion with the other.
1 1- or 2-digit number: Diameter in inches of the wheel that the tires are designed to fit. 2  There is the rare exception of metric-diameter tires, such as the use of the 390 size, which in this case would indicate a wheel of 390 mm in diameter. 3  Few tires are made to this size currently.