NTRK2 and endometriosis: The Spearman rank correlation coefficient of the association between TrKB expression in the eutopic endometrium of the endometriosis group and the dysmenorrhoea VAS score was r = 0.56, meaning there was a moderate positive association between TrKB expression in the eutopic endometrium and the dysmenorrhoea VAS score (P < 0.05); however, there was no association between TrKB expression in ovarian endometriotic lesions and the dysmenorrhoea VAS score (P > 0.05).