Necessary for the biogenesis of 40S ribosome subunits by regulating pre-rRNA processing. Non-ribosomal factor required for efficient nuclear export of the ribosomal 40S subunit. Necessary for endoreplication driven by Myc. Interacts with RpS3; the interaction is RNA-independent. Associates with free 40S ribosome subunits. Expressed in the larval body and salivary glands. Lethal at the second larval stage because of defects in pre-rRNA processing. RNAi-mediated knockdown in fat body cells results in accumulation of RpS2 and the pre-40S ribosome in the nucleus and overall decreased cell and nucleus size. RNAi-mediated knockdown in wing imaginal disk results in caspase-dependent cell-death. Belongs to the LTV1 family.