CMA1 and Merkel cell skin cancer: In a study by Nielsen et al, which employed immunohistochemical evaluation of a total of 584 patients who had undergone surgical treatment for colon cancer and had been administered antibody anti-tryptase, the multivariate analysis demonstrated that MCC was an indicator of a favorable prognosis.[21] In a study conducted by Mehdawi et al, the density of mast cells was evaluated using antibodies against tryptase and chymase.