tion ([Figure. 0](#pone-0000000-g000){ref-type="fig"}).  ![Mean value comparison of subepithelial and deep tryptase positive mast cells in healthy controls, OSF, and OSCC.](pone.0000000.g000){#pone-0000000-g000}  We observed a statistically significant increase in the number of subepithelial distribution of chymase positive MCs in OSCC group when compared to healthy controls and OSF group