SLC22A17 and cyst: To determine whether a higher concentration of mNGAL (2 mg/mL) used in 3D culture to suppress cyst enlargement of 2L3 cells (Figure 6) was resulted from the lack of posttranslational modification of mNGAL and to test whether NGAL had to be secreted and to interact with NGAL-R to induce apoptosis and further inhibit cyst progression, pN + LS and pN − LS constructs were transfected into 2L3 cells to overexpress the secreted and nonsecreted NGAL proteins (Figure 7).