The RMCE cassette present in TI{TI}Pink1KO has been has been replaced by cDNA sequence (followed by a polyA tail) encoding mutant Hsap\PINK1 carrying the pathogenic P399L variant, resulting in a locus in which the Hsap\PINK1 coding sequence is expressed under the control of endogenous Pink1 regulatory sequences.
See also Pink1hPINK1.L347P.
Hsap\PINK1Pink1.P399L is partially rescued by Scer\GAL4GH146/Hsap\PINK1UAS.cYa