CLDN9 and acromegaly: Transcriptomic groups of somatotroph PitNETs differed in the expression of genes related to epithelial-mesenchymal transition (EMT) that have a proven role in acromegaly, including CDH1 [27,28], SNAI2 [29], FLNA [30], ARRB1 [31,32], RORC [33], and ESRP1 [28], but also in other genes with an important role in EMT including CDH2, CDH3, CDH11, CTNNB1, CLDN1, CLDN3, CLDN4, CLDN9, and ZAEB1 (Figure 4A).