The aims of the study were: (i) to identify and describe the expression of Hsp20, Hsp22 and alpha-B Crystallin in exosomes, sera and peritoneal fluids from patients with ovarian cancer, endometrial cancer and endometriosis, (ii) to examine the association between exosomal sHsp and the expression of the chosen markers of immune response (namely granzyme B and perforin) in serum and peritoneal fluids. The gene discussed is PRF1; the disease is endometrial cancer.