A detailed analysis of UPF3A functions in HEK293 cells, Hela cells, mouse pluripotent cells (P19: embryonic carcinoma cell), somatic cells, and major organs, such as olfactory bulbs and testes, identified a novel function of UPF3A as a general and strong NMD repressor in mammals (Shum et al, 2016). Here, UPF3A is linked to embryonal carcinoma.