CSS Hover Reset After Background Color Change

I have a few table cells that have the following class:
.tc {
some declarations
}
.tc:hover {
background color changed
}

And I have a cell that has an onclick event that calls a function. The function gets all the cells and does this to them:
cell.style.backgroundColor = 'transparent'; // or whatever else

And then the background color of a clicked cell is changed to indicate that it has been selected. The problem is: when I change a backgroundColor of the cells, their :hover states no longer work: if I try to hover the mouse over them - nothing happens.