POU1F1 and pituitary gland adenoma: In line with previous findings, some genes identified in our integrated analysis have been closely related to the tumorigenesis of pituitary adenomas, such as GADD45G, GADD45B, MEG3 [26], POU1F1 [27], IGFBP3 [28], and CCNB1 [29]. GADD45B and GADD45G belong to GADD45 gene family, and loss of GADD45 expression has been observed in various human cancers [30].