RILP (Rab interacting lysosomal protein) is a Rab7 effector protein that plays crucial roles in endolysosomal trafficking and cellular homeostasis. RILP regulates lysosomal positioning by recruiting dynein-dynactin motor complexes to Rab7-containing late endosomes and lysosomes, promoting their retrograde transport to perinuclear regions 1. This positioning is functionally significant, as RILP-mediated lysosomal clustering enhances LRRK2-dependent Rab10 phosphorylation in the perinuclear area 1. RILP modulates cholesterol homeostasis by competitively inhibiting VAP-ORP1L interactions, thereby blocking cholesterol transport from endolysosomes to the endoplasmic reticulum and inducing cholesterol accumulation in lysosomes, which triggers autophagy 2. The protein also responds to pH changes, with V-ATPase assembly promoting RILP-mediated Rab7 stabilization during late endosomal pH neutralization 3. Structurally, RILP forms homodimers that interact with single Rab12 molecules through its Rab homology domain 4. In disease contexts, RILP exhibits tumor suppressor activity in osteosarcoma by inhibiting the PI3K/AKT/mTOR pathway through Grb10-mediated mechanisms, suppressing cell proliferation and metastasis while promoting autophagy 5. RILP's multifaceted roles in organelle positioning, cholesterol trafficking, and autophagy regulation make it a critical component of cellular homeostasis.