Interesting Fact 1: Rabbi Akiva's Brother-in-Law

We have certain mourning practices during Sefirat HaOmer because of the 24,000 students of Rabbi Akiva who all died at this time. However, immediately afterwards Rabbi Akiva went and taught another five Rabbis in the South, and (almost) the entire Oral Torah as we have it today developed from what he taught those students.

Here is an interesting fact about Rabbi Akiva.

Everyone knows that his father in law was Kalba Savua. But did you know that Rabbi Akiva's brother in law was also a Tanna and is also mentioned in the Mishnayot?

אמר רבי יוחנן בן ישוע בן חמיו של רבי עקיבה, כדברי בן עזאי, כן נחלקו וכן גמרו.

Rabbi Yochanan ben Yehoshua, son of Rabbi Akiva's father-in-law said, [the reality is] like the words of Ben Azai: They [Beit Hillel and Beit Shammai] argued [about the status of Shir HaShirim], and they concluded [that Shir HaShirim is part of the Tanach]

Yadayim 3:4

Not only is he mentioned, but he is arguing on the opinion of Rabbi Akiva here (who claimed that there was never any dispute about the status of Shir HaShirim).