TTK and lung adenocarcinoma: Several hub genes, such as BUB1B, CDC45, BUB1, TTK, TOP2A, MCM2, NDC80, and DTL, have been reported to be associated with poor prognosis in patients with lung adenocarcinoma (Hayama et al., 2006; He et al., 2019; Liu et al., 2017; Perez-Pea et al., 2017; Song et al., 2018; Sun et al., 2020).