epididymis secretory sperm binding protein HE4 major epididymis-specific protein E4 WAP5 epididymal protein 4 EDDM4 dJ461P17.6 epididymis-specific, whey-acidic protein type, four-disulfide core WAP four-disulfide core domain protein 2 WAP domain containing protein HE4-V4 epididymal secretory protein E4 human epididymis protein 4 putative protease inhibitor WAP5