## Problem 018 — rank:215

**Title:** Selective autophagy

**Added binding assumptions (LaTeX):**

```latex
The capacity inequality has units of membrane area per unit time and is an imposed model constraint, not an identity following from the selectivity ratios. Define instantaneous versus time-averaged flux consistently. An overload threshold requires a fixed incoming-load family and a stability or clearance criterion for its queue; pairwise selectivity alone cannot determine that threshold.
```

**Direct edits:** 0. **Fresh external checks:** None; supplied sources retained as provenance.