The RMCE cassette of the TI{CRIMIC.GT14}Cdk4CR99906 insertion has been replaced with a TI{FFL.1} cassette that is in gene-trap (GT) orientation relative to Cdk4. This is expected to truncate the Cdk4 protein and to result in the expression of a separate mCherry protein under the control of endogenous Cdk4 regulatory sequences.