HTRA3 and neoplasm: The interplay between epithelial and stromal components has also been underlined by studies examining bone morphogenetic protein (BMP) antagonists (51, 81), hypothesizing that CRC cells in the tumor microenvironment can only flourish in a milieu devoid of BMP signaling, this was characterized immunohistochemically by a shift in HTRA3 expression patterns (decreased stromal staining and increased epithelial staining).