Fill in the Blank in the Following Paragraph Regarding the Extracellular

Short Answer

Fill in the blank in the following paragraph regarding the extracellular matrix. Do not use abbreviations.
"The extracellular matrix of connective tissues in animals is primarily made and secreted by the … family of cells, although they may have more specific names in certain tissues. Being common in connective tissues, these cells can also migrate and proliferate if need be."