Apart from the above, in our analysis of the differences in the concentrations of the immunological factors in serum and cystic fluid, between the cancer and non-cancer groups of patients with cystic tumors, only the cancer group showed significantly lower sIL-6Ra, sVEGFR-2, PECAM-1, and SCF in the cystic fluid than in the serum. Here, PECAM1 is linked to cystic neoplasm.