In this task, you are given a sentence. You are expected to recognize the name of gene or protein. Although there might be several correct answers, you need to write one of them.

[Q]:  Tubular dysfunction in renal lithiasis : cause or consequence ? ] To investigate whether overall tubular dysfunction is encountered in a particular subgroup of patients with urolithiasis , the following parameters of renal tubular function have been measured in fasting morning urine in 124 male stone formers : excretion of lysozyme and gamma - glutamyl transpeptidase ( gamma - GT ) , fractional excretion ( FE ) or glucose , insulin , bicarbonate after an alkali load , and theoretical phosphate threshold ( TmP / GFR ) .
[A]: gamma - GT


[Q]:  Three experiments using 20 microM 2 - ( hydroxyamino ) - 1 - methyl - 6 - phenylimidazo [ 4 , 5 - b ] pyridine ( N - OH - PhIP ) were performed to induce mutations in the dihydrofolate reductase ( DHFR ) gene of a hemizygous Chinese hamster ovary ( CHO ) cell line ( UA21 ) .
[A]: dihydrofolate reductase


[Q]:  As a test of this hypothesis , we predicted that mice which have altered expression of class I gene products , the beta2 - microglobulin knockout mice , [ beta2m ( - / - ) ] , would develop Fe overload .
[A]:
beta2 - microglobulin