CXCR4 protein concentrations are greater in caruncle and intercaruncle tissue on Day 35 compared to Day 50 of pregnancy. Equal concentrations of caruncle and intercaruncle protein lysate from Days 35 and 50 of gestation were subjected to SDS-PAGE and Western blot analysis was performed to verify expression of CXCR4. Data are representative blots of a minimum of 3 ewes per day. CXCR4 was greater in caruncle (A) and intercaruncle (B) tissues on Day 35 compared to Day 50 of gestation. The same protein samples were also probed for actin to further verify equal loading of protein. Signals on Western blots were scanned on a STORM imager, converted to densitometric values, and analyzed. Values represent the mean ± SEM. Significant differences (P < 0.05) in caruncle (C) and intercaruncle tissues (D) from ewes on Day 35 and 50 are indicated by an asterisk.