gunzip - Unzip files in subdirectories bash -

i have directory called test1 contains multiple directories. in each directory test1/*/, there *.gz file want unzip. tried writing code doesn't work, appreciated.

for folder in test1/*/; find . -name "*.gz" | while read filename; gunzip -d $filename;done ;done 

gunzip test1/*/*.gz 

gunzip extract file in directory in.