SERPINE1 and hyperinsulinemic hypoglycemia, familial, 4: DNA gel blot analysis of a non-fluorescent pai1 dcl2 dcl3 dcl4 line indicated a nearly complete loss of CCG methylation monitored by MspI cleavage and partially reduced CG methylation monitored by HpaII cleavage at PAI2 relative to the fluorescent parental line, consistent with the reversion of tryptophan deficiency phenotypes (Figure 4).