COL2A1 and Merkel cell skin cancer: As overloading of mandibular condyles increases the expression of interleukin (IL)-1 β, matrix metalloproteinases 13 (MMP13), and aggrecanase (ADAMTS5) and decreases the expression of tissue inhibitors of metalloproteinases (TIMP3) and COL2A1, this study examined whether the expression of these genes is altered in MCC cells under loading conditions using qRT-PCR analysis18.