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.
For example, a tire that measures 26 x 1.75 inches has an ISO/ETRTO number of 47-559, while a tire measuring 700 x 23 mm is equal to 23-622. The first number gives the inside width of the tire, which can be compressed or expanded somewhat to fit a range of wheel widths.