CASC9 and liver cancer: Increasing evidence has shown that lncRNAs such as lnc ZEB2-19,[9] lnc TSPAN12,[13] lnc CCNH-8,[14] and linc01116,[15] are abnormally expressed in liver cancer and commonly used as biomarker for the diagnosis and prognosis of liver cancer, such as CASC9,[16] FTO-IT1,[17] SOCS2-AS1.[18] Among these lncRNAs, ATG9B-4 was highly expressed in liver cancer and promoted the growth, TNM stage and metastasis of liver cancer in our previous study.[10] However, the mechanism by which ATG9B-4 regulates malignant characteristics of liver cancer still needs to be further studied.