KISS1R and neoplasm: There were no significant changes in KISS protein expression (Figure 4A) between stages of tumor development, according to FIGO classification (median test: chisq = 10.634, df = 7, p = 0.155; rgamma = −0.065; n = 214; p = 0.261), but we found that GPR54 expression increased with the stage of tumor advancement (Figure 4B) (i.e., the difference between developmental stages was significant at the accepted level of probability—median test: chisq = 20.965, df = 7, p = 0.004).