TMEFF2 and Familial prostate cancer: Zhao et al. [52] observed TMEFF2 in the lysosomes of PC3 prostate cancer cells; as TMEFF2 lacks the typical cell-surface protein internalization motifs found in type I and II receptor proteins which canonically trigger their turnover through lysosomal degradation, the presence of a novel internalization signal in TMEFF2 has been suggested.