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.
Example size: 225/45R17. The first three numbers in a typical size (225/45R17) are the tire's indicated section width in millimeters, measured from sidewall to sidewall. If you are familiar with measurements in inches, the section width in millimeters can be converted into inches by dividing it by 25.4. The second pair of numbers (225/45R17) is the tire's aspect ratio or profile. This percentage represents the ratio of sidewall's section height to the tire's section width.