Collectively, our data suggest that MALAT1 can interact together with PTBP1 and PSF to form a functional module and that, after the module formation, MALAT1 may direct localization of PSF, as well as that of PTBP1 in some cases, on pre-mRNAs, thereby operating in the modulation of pre-mRNA AS in HCC cells. The gene discussed is MALAT1; the disease is hepatocellular carcinoma.