Returns the cell's DataValidation object if one exists. Otherwise, returns 'null'.

 public DataValidation DataValidation{ get; set; }
Public Property DataValidation() As DataValidation

When setting the dataValidation, if the value you're setting it to uses a local reference or area in a formula (i.e. "=A5:B7"), then the cell will adjust those local references accordingly based on the cell's location. The original dataValidation object you assigned the cell to use will remain unaffected.

DataValidation dv = cellA1.DataValidation;
Dim dv As DataValidation = cellA1.DataValidation