Western blotting demonstrated that serum withdrawal increased LC3-I to LC3-II conversion (p < 0.001, human NP and AF; p = 0.042, rat NP) and decreased p62/SQSTM1 expression (p = 0.001, human NP; p = 0.007, rat NP), both indicating enhanced autophagy; therefore, autophagic changes were common between human and rat discs and between NP and AF cells (Figure 1D,E). Here, SQSTM1 is linked to atrial fibrillation.