MAPK3 and pachyonychia congenita: We found that LAMTOR3, as a scaffold protein between MEK1 and ERK1, was the target of circ_0075829/miR‐1287‐5p in PC progression, because the inhibition of miR‐1287‐5p could partially reverse the decline in LAMTOR3/p‐ERK caused by the knockdown of circ_0075829.