CXCL12 and disease recurrence: ↑ in BlCa patients (Yang et al., 2015) vs. ↓ in BlCa patients (Du et al., 2021c); ↑ in undifferentiated tumors (Batsi et al., 2014); ↑ in higher stage tumors (Batsi et al., 2014); ↑ in recurrent disease (Batsi et al., 2014); Normal tissue did not express CXCL12 (Yang et al., 2015)