PCNA and cyst: Nevertheless, the renal level of NGAL protein in Pkd1L3/L3 × NGALTg/Tg mice was approximately 2-fold of that in Pkd1L3/L3 × NGAL+/+ mice, and overexpression of NGAL led to markedly lower levels of PCNA in Pkd1L3/L3 × NGALTg/Tg than in Pkd1L3/L3 × NGAL+/+ mice and further inhibited cyst growth and prolonged survival days [31].