In contrast to hypergravity, the simulated microgravity (≤ 0.012 g for 24 h) in a fast-rotating 2D clinostat (Figure 3B) down-regulated the eNOs-sGC-MRP4/MRP5 signaling in pigmented non-metastatic 1F6 melanoma cells [82]. Here, ABCC4 is linked to melanoma.