>>13635024there are several common genetic modifications
one is for the plant to express BT toxin, which is some kind of bacterial toxin that kills insects when they eat it
another is herbicide (glyphosate) resistance so that you can spray the field with herbicide to kill of weeds but not the crop
but there are other modifications that improve tolerance to drought, soil salinity, or other conditions, and some that improve the nutritional value of the corn cob
all of those modifications are different because different transgenes are being expressed in each case. It's conceivable that one gene product could be bad for humans, but you can't just lump that in under "ALL GMOs"