Multiple choice Which of the following mice strains are deficient in NK cells? SJL Beige Nude MRL-lpr/lpr Moth-eaten viable Reveal answer Fill a bubble to check yourself B Correct answer Explanation NK cells are spontaneously cytotoxic for certain tumor cell lines and express CD16, the low affinity Fc gamma RIII. Beige mice congenitally lack NK cells and die with spontaneous tumors earlier than their non-deficient heterozygous+/bg littermates.