UPK3A and breast cancer: Our study showed increased concentration of UPIIIa in plasma (p≤0.001) and in urine (p≤0.001) of BC patients in comparison to healthy control group C. Elevated UPIIIa level in urine of BC patients was previously described only by Lai et al. The results of this study showed high sensitivity (83%) and specificity (83%) of this marker (UPIIIa) in urine [11].