In the combination treatment of RAPA (1 nM) with HF (2.5 nM), the addition of 1 mM proline decreased the combination inhibition from 79.26 ± 1.0% to 70.08 ± 1.80% (P ˂ 0.0001, n = 5), or recovered 11.58% of the total inhibition that was much lower than that (∼57%) in cultures treated with HF alone, suggesting a decreased effect of proline depletion on the combination action of HF and RAPA. The gene discussed is TRERF1; the disease is hydrops fetalis.