At present, some patients with heart disease have not been able to completely get rid of the pain, and even if a heart transplant is performed, the body may have a rejection reaction. New research has found that the use of human skin cells can create heart cells. Heart disease brings the gospel. Which of the following, if true, cannot weaken the above conclusion? ['Experiments have found that if skin cells are implanted into the heart muscle along with other cells, symptoms of weakened heart function are prone to occur.', 'The implanted skin cells must be carefully screened in advance, otherwise, the cells may develop into tumors in the patient and even cause complications.', 'Animal experiments show that compared with other cells, skin cells have no rejection after implantation into the myocardium, resulting in a decrease in arrhythmia.', "In the experiment, the researchers used the patient's skin cells to grow heart cells, but this process took a long time to create enough new cells."]