PITX1 and facioscapulohumeral muscular dystrophy: Combined with the fact that this 30-bp sequence is not completely conserved between mouse and human, that the expected ChIP-seq peak was not found over the region corresponding to this 30-bp sequence in humans, or anywhere near PITX1 [11], and the fact that PITX1 was not found to be strongly upregulated by DUX4 in various human cell systems [11, 19] (or even mouse systems [22, 35, 36]), these data argue strongly against the model in which FSHD is caused by DUX4-mediated overexpression of PITX1 [10].